Methods, compositions and systems for preventing an adverse reaction of the skin to the presence of a skin-sensitizing and/or skin-irritating agent by administering an effective amount of phenoxyacetic acid and/or a lower alkyl ester thereof to a warm blooded animal.

The present invention relates to methods and compositions for preventing adverse reactions of the skin to skin-sensitizing or skin-irritating agents.
The skin is susceptible to penetration by agents that sensitize the skin or irritate the skin. As used herein the term xe2x80x9cskin-sensitizing agentxe2x80x9d is a substance that generally causes the formation of memory cells which recognize future contact with the sensitizing agent. Such future contact can result in an adverse reaction, both locally and at remote sites on the body. In general, a xe2x80x9cskin-irritating agentxe2x80x9d is a substance (e.g. soap) that causes an immediate and generally localized adverse response. The response is typically in the form of redness and/or inflammation and does not extend beyond the immediate area of contact nor does it cause the formation of memory cells. As used herein, the term xe2x80x9cadverse skin reaction preventing or treating agentxe2x80x9d shall mean collectively agents used in the present invention against skin-sensitizing agents and/or skin-irritating agents.
Allergic reactions of the skin to skin-sensitizing agents, known as allergic contact dermatitis (ACD), are immune responses that occur in the skin. The response is the result of the penetration of the skin by a foreign substance (e.g. hapten or antigen) that provokes a skin sensitization reaction. ACD is a two phase process involving an initial induction phase followed by an elicitation phase.
The induction phase occurs immediately after first time exposure of the skin to the hapten or antigen and is characterized by the formation of immune memory cells that can subsequently recognize the specific hapten or antigen which previously entered the skin for the first time.
The elicitation phase occurs when the skin is subsequently re-exposed to the original hapten or antigen. In the elicitation phase, the skin provides an overt reaction to the presence of the hapten or antigen in the form of a skin inflammatory response.
ACD generally results in a life-time persistent memory for the specific hapten or antigen. Thus, when the skin is exposed to the hapten or antigen at a subsequent time, there is typically an immediate and often severe skin inflammatory response.
Agents that cause allergic contact dermatitis are varied and numerous and include, for example, metals (e.g. nickel, chromium, cobalt and the like) fragrances, chemicals, cosmetics, textiles, pesticides, plastics, pollen and the like (see, for example, R.J.G. Rycroft et al. xe2x80x9cTextbook of Contact Dermatitisxe2x80x9d). Therapeutic agents such as drugs may also cause allergic contact dermatitis particularly when administered transdermally.
Transdermal delivery of drugs provides many advantages over alternate routes of administration. Transdermal delivery systems (TDS) for delivery of drugs or other beneficial agents are well-known (see, for example, U.S. Pat. Nos. 3,598,122, 3,598,123, 4,286,592, 4,314,557, 4,379,454, 4,599,222 and 4,573,995, which are each incorporated herein by reference). A TDS is generally composed of the following components: (a) xe2x80x9cbasic componentsxe2x80x9d, including backing, matrix reservoir, and an optional separate adhesive layer; (b) the drug or other therapeutic agent; (c) xe2x80x9cadditivesxe2x80x9d, including solubilizers, plasticizers and permeation enhancers; and (d) xe2x80x9cimpuritiesxe2x80x9d such as residual amounts of monomers, initiators, cross-linkers, etc., from the polymerization process during fabrication of the basic components.
The conditions under which TDS are-administered are highly conducive to the induction of skin allergic reactions, and the following skin reactions may be expected to occur:
1. Irritant reactions to the drug, an additive, an impurity, or a combination thereof;
2. Allergic reactions, especially to the low molecular weight components (drug, additive, impurity, adhesive);
3. Local sweat retention syndrome resulting from prolonged skin occlusion which causes blocking of sweat ducts.
Allergic contact dermatitis presents a significant problem in the transdermal administration of therapeutic agents. It is well known that many drugs, including some currently marketed in the United States (e.g. clonidine) sensitize the skin when used in a transdermal delivery system. Skin sensitization may be produced not only by the transdermally delivered drug, but also by a non-sensitizing drug combined with skin sensitizing permeation enhancers, or a combination of a sensitizing drug and a sensitizing permeation enhancer. Penetration of these sensitizing agents into the skin and the resulting adverse reaction of the skin may persist well beyond the time that the transdermal patch is removed from the skin. The reaction of the skin may be a source of discomfort and a clinical complication in a patient suffering from such a reaction.
Unlike the response induced by skin-sensitizing agents, the non-allergic response to skin-irritating agents is immediate and localized and does not invoke activation of the immune system through the production of immune memory cells.
The most common response associated with skin-irritating agents is the onset of inflammation. The main steps of the inflammatory response include, the neurologic phase, the vascular phase and the cellular phase. In the neurologic phase transient vasoconstriction occurs typically within about 30 seconds of contact with the skin-irritating agent. Within about one to six minutes of contact, vasodilation occurs followed by the margination of neutrophils in the vessels and diapedesis, the outward passage of corpuscular elements through intact vessel walls.
The non-immune response to a skin-irritating agent is the result of a substance that causes direct toxic damage to the skin without preceding allergic sensitization. The response to contact is dependent upon the nature of the skin, the skin-irritating agent, its concentration, the situs of contact on the body and environmental factors such as humidity and temperature. Examples of potential skin-irritating agents include water, skin cleansers, industrial cleaning agents, alkalis, acids, oils, organic solvents, oxidizing agents, reducing agents, plant matter, animal matter, combinations thereof and the like.
Efforts have been made to address the problem of allergic contact dermatitis by prophylactically treating the skin to prevent the onset of the induction phase of ACD and/or to therapeutically prevent or reduce the adverse effects of the elicitation phase of ACD. For example, U.S. Pat. No. 5,202,130 discloses that lanthanide ions and organic calcium channel blockers individually can be used for the treatment of contact allergic dermatitis.
Wolfgang Diezel et al., J. Invest. Derm., Vol. 93, No. 3, pp. 322-326 (September 1989) discloses the sensitization of mice with 1-chloro-2, 4-dinitrobenzene and subsequent treatment with lanthanum citrate and diltiazem hydrochloride to prevent the onset of the induction phase of the sensitizing agent. Philip W. Ledger, et al., U.S. Pat. No. 5,120,545 disclose the prevention of skin sensitization by the administration of an antigen processing-inhibiting agent such as ammonium chloride. A method of preventing contact sensitization using steroids (e.g. corticosteroid and glucocorticoid carboxylic acid esters) is disclosed, for example, in Alfred Amkraut, U.S. Pat. No. 5,118, 509 and Peter M. Ross, et al., U.S. Pat. No. 4,897,260.
A method of reducing the adverse effects of administering a sensitizing or irritating drug by using methyl nicotinate is disclosed in Michel Cormier et al., U.S. Pat. No. 5,451,407.
Methods of treating ACD through the blocking of the elicitation phase after initial exposure to a drug is disclosed, for example, in John McFadden, et al., J. Invest. Derm., Vol. 99, No. 6, pp. 784-786 (December 1992). Tuberculin-induced delayed-type hypersensitivity reaction in human skin was inhibited by topical application of verapamil hydrochloride prior to or concurrent with challenge with tuberculin.
Also, Richard L. Gallo, et al., Arch. Dermatol., Vol. 125, pp. 502-506 (April 1989) discloses the administration of the diuretic amiloride hydrochloride as a topical anti-inflammatory agent in the treatment of ACD, particularly mice sensitized with 2,4,6-trinitrobenzene.
As disclosed in commonly assigned U.S. Ser. No. 08/198,003 filed Feb. 17, 1994, and references cited therein, irradiation of skin with ultraviolet light B (UVB) is known to be immunosuppressive. These UVB effects are thought to be mediated, in part, by the UVB-induced isomerization of trans-urocanic acid (trans-UCA), a molecule which makes up about 0.5% of the total dry weight in the upper layers of human epidermis, to cis-urocanic acid (cis-UCA). Cis-UCA is known to have various immunosuppressive actions in vivo in a number of experimental systems and is believed to act through histamine-like receptors in the skin. More recently, it has been shown that the UVB impairment of the induction phase of allergic contact dermatitis to epicutaneously applied haptens in certain mouse strains depended on the participation of the cytokine, tumor necrosis factor-a (TNFa). It has been suggested that local release of TNFa may inhibit sensitization by trapping epidermal:Langerhans cells and preventing them from reaching the draining lymph node where they activate T. cells.
As further disclosed in U.S. Ser. No. 08/198,003, mast cell degranulators such as cis-urocanic acid are effective for preventing or inhibiting the skin sensitizing effect of a transdermally administered therapeutic agent.
Hand eczema is a common clinical condition treated and evaluated by dermatologists. There are thought to be two principal causes of eczema, although typically eczema is caused by a combination of factors. One factor is a topic dermatitis, a multifactorial genetic disorder. A topic dermatitis is common in children, affecting 3% of all infants. Remissions are frequent in childhood, but the eczema is likely to recur as a chronic disease in adulthood. Other factors include external irritants (chemical/physical); contact allergy; infection; venous stasis; scratching; sweating; autosensitization and stress. The treatment of eczema has been made easier by the introduction of topical steroids.
Over the past ten years, research has uncovered many epidemiological and risk factors related to specific environmental exposures. In particular, health care professionals suffer persistent irritation from the frequent use of medicated hand washes attributable to active agents in the formulations, such as surfactants (e.g., sodium lauryl sulfate), and/or the effects of repeated wetting and drying of hands.
The use of oxidative dyes, e.g., p-phenylenediamine in hair coloring salons as well as other hair conditioning products may result in both skin irritation and sensitization reactions among a susceptible segment of users and hair care professionals. Finally, there are many otherwise safe topical medicaments that contain active ingredients (e.g., retinoic acid, lactic acid, capsaicin and topical non-steroidal anti-inflammatory drugs (NSAID)) used in sports medicine, for treatment of the rheumatic and skeleto-muscular pains, and for anti-aging and the like that cause skin irritation and sensitization reactions in some fraction of treated patients.
Topical steroids and non-steroidal anti-inflammatories have been proposed for the therapeutic treatment of eczema. However, such agents, often obtained only with a prescription, cannot be added to medicaments and skin care products to prevent skin irritation and skin sensitization due to the active ingredients contained therein.
Despite these efforts and the knowledge gained regarding the cause of ACD, there remains a need to develop compositions which effectively prevent the onset of ACD or reduce the adverse affects of ACD after the person has been sensitized to an agent, as for example, a transdermally administered agent such as a drug or agents contained within commercial products such as hair lotions and the like which can cause ACD. There is likewise the need to develop compositions which effectively prevent reactions to skin-irritating agents.
Applicants have gained the knowledge that there is a distinct process step implicated in the immune response associated with allergic contact dermatitis, which when interfered with, results in the prevention and/or treatment of ACD. This process step referred to herein as cellular signal transduction, is believed responsible for the acquisition of memory by T-lymphocytes, for the cytokine-mediated regulation of antigen presentation and for other cellular processes as well. Applicants have discovered that lower alkyl esters of phenoxyacetic acid interferes with cellular signal transduction and therefore can be used to prevent or treat allergic contact dermatitis.
Applicants have also discovered that phenoxyacetic acid and lower alkyl esters of phenoxyacetic acid when administered in appropriate amounts, alone or as part of commercial products. (e.g. hair lotions), achieve significant improvement in the desensitization of a patient""s skin and prevent inflammation of the skin including the symptoms associated with eczema. As a result, the reaction of the skin to skin-sensitizing agents or skin-irritating agents is better controlled. The present invention therefore provides prevention of an adverse reaction to the skin.
The present invention is generally directed to methods of preventing allergic contact dermatitis (ACD) and/or skin irritation including eczema and compounds, compositions and systems to accomplish the same. In one aspect of the invention a method is provided for preventing an adverse reaction of the skin caused by the presence of skin-sensitizing agents such as therapeutic agents (e.g. drugs) metals, fragrances, cosmetics, hair preparations, textiles, pollen, pesticides, plastics, combinations thereof and the like, or skin-irritating agents such as cleansers, cleaning agents, alkalis, acids, oils and the like.
The present invention is also applicable to ACD induced by the transdermal administration of an agent, as for example, a therapeutic agent such as a drug. In general, the present invention includes a method of preventing an adverse reaction of the skin to the presence of at least one of a skin-sensitizing agent and skin-irritating agent including eczema comprising administering to a said warm-blooded animal an effective amount of an adverse skin preventing agent comprising phenoxyacetic acid and lower alkyl esters thereof having the Formula (1)
wherein R is hydrogen or a lower alkyl group. Lower alkyl as defined herein shall include straight and branched chain alkyl groups having from 1 to 6, preferably from 1 to 4 carbon atoms. The preferred group for R is methyl. Ph is a phenyl group.
The skin-sensitizing or skin-irritating agents employed in the present invention can be prepared in the form of a composition containing one or more additives including skin permeation enhancers, excipients and the like.
The adverse skin reaction preventing agents of the present invention may be administered topically in the form of lotions, creams, sprays and the like, by non-cutaneous routes as well as through the use of transdermal patches. In transdermal applications, the agents may be administered from a single reservoir also containing a therapeutic agent or preferably from a separate reservoir of a transdermal patch.
In addition the agents of the present invention may be added to conventional products which are applied to or come into contact with the skin such as hair treatments (e.g. shampoos, conditioners and the like), skin lotions, cream, salves and the like.
The present invention is in part directed to methods and systems for preventing the onset of skin sensitization reactions caused by allergic contact dermatitis by treatment before, after or during the induction phase of sensitization and for alleviating this condition once ACD has progressed to the elicitation phase. In one aspect of the invention the skin is treated with a compound selected from phenoxyacetic acid and lower alkyl esters thereof alone or as part of a product which is applied to or contacts the skin. Such products include, but are not limited to, anti-aging compositions (e.g. retinoids and alpha-hydroxy acids), hair treatment preparations such as shampoos and conditioners, soaps whether in liquid or solid form, detergents, perfumes, cosmetics, household and industrial cleaners, organic solvents and the like. Such products can be in the form of liquids, lotions, creams, gels, salves, suspensions, emulsions and the like.
The employment of a composition containing such adverse skin reaction preventing agents provides desensitization of the skin to the presence of skin-sensitizing agents as also encountered from transdermal systems before, after or during the transdermal administration of the therapeutic agent.
In another aspect of the present invention, the agents and compositions containing the same are also effective in preventing adverse responses caused by skin-irritating agents such as household and industrial cleansers, organic solvents and the like. These agents are effective in disrupting the inflammatory response by limiting the ability of the skin-irritating agent to elicit the neurologic, vascular and/or cellular phase of inflammation.
The above methods are useful for preventing skin sensitization or inflammation produced by a variety of skin-sensitizing agents such as, for example, a drug selected from, but not limited to, the following group: (a) an angiotensin converting enzyme inhibitor; (b) a beta adrenergic receptor blocker; (c) an anti-hypertensive drug other than an angiotensin converting enzyme inhibitor or a beta adrenergic receptor blocker; (d) an anti-histamine; (e) an anti-asthmatic; (f) a non-steroidal anti-inflammatory drug; (g) a central nervous system active drug; (h) a weight control drug; (i) an anticoagulant; (j) a potassium control drug; (k) an immunomodulatory drug; (1) a decongestant; and (m) proteins and peptides such as insulin and thyrotropin-releasing hormone.
More specifically, the therapeutic agents for administration in accordance with the present invention include all of the major therapeutic areas, including, but not limited to: anti-infectives such as antibiotics and antivirals; analgesics and analgesic combinations (such as capsaicin); anorexics; antiarthritics; anti-asthmatics (such as albuterol, metaproterenol, ketotifen and terbutaline); anticoagulants (such as urokinase); anticonvulsants; antidepressants; anti-diabetics; antidiarrheals; antihistamines (such as chlorpheniramine and diphenhydramine); anti-inflammatory agents (such as ketoprofen, prostaglandins, flurbiprofen, diclofenac, indomethacin, piroxicam and ibuprofen); antimigrane agents; anti-motion sickness preparations; antinauseants; antineoplastics; antiparkinsonism drugs; antipruritics; antipsychotics; antipyretics; antispasmodics, including gastrointestinal and urinary; anticholinergics; sympathomimetics; xanthine derivatives; cardiovascular agents, including angiotensin converting enzyme inhibitors (such as captropril and fosinopril); beta blockers (such as nadolol, timolol, propranolol and alprenolol); antiarrythmics; antihypertensives (such as clonidine); vasodilators, including general, coronary, peripheral and cerebral; central nervous acting agents (such as fluphenazine, trifluoperazine, haloperidol, Xanaxxe2x80x3, Libriumxe2x80x3, Valiumxe2x80x3); cough and cold preparations; decongestants; diagnostics; hormones; hypnotics; muscle relaxants; parasympatholytics; parasympathomimetics; psychostimulants; sedatives; weight control and appetite suppressive drugs (such as mazindol) and tranquilizers.
The above methods are also useful for preventing skin irritation produced by a variety of skin-irritating agents as previously described including but not limited to, eczema causing agents (e.g. rubber accelerators), household and industrial cleansers, water, organic solvents, oxidizing and/or reducing agents, alkalis, acids, oils, plant matter, animal matter and the like.
The present invention further provides an article useful for preventing the skin sensitizing or inflammatory effect of a component of a transdermal drug delivery system, where the component is either a drug, a skin permeation enhancer, or other materials or a combination of the same and the like, the article comprising:
(a) a transdermal delivery system comprising a therapeutic agent (e.g. a drug) of interest; and
(b) an effective amount of phenoxyacetic acid or lower alkyl ester thereof.
The adverse skin reaction preventing agents can also be administered in a transdermal or a controlled-release device. Examples of transdermal devices and delivery systems which may be used are disclosed in Bodde, H. E. et al., Crit. Rev. Ther. Drug Carrier Syst. 6:87-115 (1989); and in U.S. Pat. No. 3,598,122, 3,598,123, 4,286,592, 4,314,557, 4,379,454, 4,559,222, 4,573,995, which references are hereby incorporated by reference.
The delivery system may include a first transdermal device comprising a matrix for placing the adverse skin reaction preventing agents in transmitting relationship to the skin. A second transdermal device may be used to place the therapeutic agent in transmitting relationship to the skin after the adverse reaction preventing agent has been transdermally administered to the skin. The first and second transdermal devices may be incorporated into a single transdermal patch.
The adverse skin reaction preventing agents are administered by themselves, as part of a product applied to or coming into contact with the skin (e.g. shampoo), as part of a topical application composition (e.g. lotion, cream and the like) or in transdermal systems in combination with a therapeutic agent of interest. When administered alone, these agents may be administered topically or non-cutaneously such as intradermally, intravenously, intramuscularly, orally or intra-peritoneally. The agents of the present invention can be incorporated into a pharmaceutically acceptable composition for topical application to the skin in the form of lotions, creams gels and the like. Useful carriers for the preparations of such compositions include water, ethanol, gels and the like. The agents of the present invention may also be administered as part of a preparation (e.g. shampoo) which is applied to or in contact with the skin.
The precise formulation of the transdermally administered therapeutic agent (e.g. a drug) and the adverse skin reaction preventing agents of the present invention can be designed to deliver the drug and the agents at the desired fluxes and can be in numerous forms, including, without limitation, ointments, gels and creams. Aqueous formulations, in particular gels, typically comprise water and from about 1 to 2.5% (w/w) of a gelling agent such as hydroxyethylcellulose or hydroxypropylmethylcellulose (HPMC). Typical non-aqueous gels comprise silicone fluid or mineral oil. The mineral oil may also have from about 1 to 2% (w/w) of a gelling agent such as colloidal silicon dioxide. The suitability of a particular gel composition depends on. the compatibility of its constituents with the drug (with or without a permeation enhancer) and the adverse skin reaction preventing agents.
In another embodiment, the agents of the present invention are delivered to the skin alone to prevent skin-sensitization and/or skin irritation or prior to the administration of the therapeutic drug or drugs. Such prior administration can be via transdermal application using a device as described above, via topical application, intracutaneous injection, and the like.
In yet another embodiment, the agents are delivered by another non-cutaneous route and method of delivery, either concurrently with, or prior to, the transdermal administration of the therapeutic drug.
In embodiments of the invention where the adverse skin reaction preventing agent is administered to prevent irritation of the skin, the composition containing the same is preferably in the form of a lotion, cream or other readily applied topical formulation.
In all of the above embodiments, the dosage of the adverse skin reaction preventing agents administered will be dependent upon the agent, the age, health, and weight of the recipient, kind of concurrent treatment, if any, and frequency of treatment.
The methods and compositions within the scope of this invention include all compositions and methods wherein the adverse skin reaction preventing agents are contained in an amount effective to achieve their intended purpose. While individual needs vary, determination of optimal ranges of effective amounts of each component is within the skill of the art.
For transdermal administration, typical effective-dosages of the agents to prevent ACD by a sensitizing drug will depend on their permeation through human skin, and are a function of the physical properties of the permeant, including the partition coefficient of the permeant between solvent and skin, molecular weight and melting point. In general, the maximum flux that can be obtained from any permeant occurs from saturated solutions. Equations have been derived that predict accurately the maximum flux given the partition coefficient, molecular weight and melting point of the permeant as described in, for example, xe2x80x9cTREATISE ON CONTROLLED DRUG DELIVERYxe2x80x9d, A. Kydonieus, ed., Marcel Dekker, Inc., New York, 1991, in particular, p. 370, equations 3a and 4a and p. 34, FIG. 2, incorporated herein by reference. For the transdermal delivery of phenoxyacetic acid and lower alkyl esters thereof, the expected maximum flux that can be delivered locally to skin is in the range of from about 1 to 50 xcexcg/cm2/hr. These values are dependent, for example on varying skin age, skin type and skin condition. The preferred range for the maximum flux of the active ingredient is from about 5 to 25 xcexcg/cm2/hr. Accordingly, as will be understood by those skilled in the art, the delivery of a particular agent, is controlled by the percent saturation of that agent in the chosen vehicle.
The amount of phenoxyacetic acid and lower alkyl esters thereof which can be delivered to prevent ACD will vary from patient to patient. For example, the amount of the present agents delivered from a gel formulation (2.5% HPMC in 75% ethanol) is from about 0.1 to 10% by weight, and preferably from about 0.25% to 2.0% by weight.
For administration of the adverse skin reaction preventing agents to prevent skin irritation, the dosage will vary as described. For example for topical application, the amount of phenoxyacetic acid and lower alkyl esters thereof is from about 0.1 to 2.0 percent by weight, preferably from about 0.25 to 1.0 percent by weight based on the total weight of the composition.
When combined with a conventional product applied to or in contact with the skin, the amount of the active ingredient is typically from about 0.1 to 2.0 percent by weight of the total composition.

Prophylactic and therapeutic treatment of skin sensitization and irritation


A coated, optically brightened printing paper includes a coating base paper and an applied coating containing a pigment, a binder, and color coating supplements, with an optical brightener containing a derivative of diaminostilbene disulfonic acid applied to the outer side of the color coating. The coating base paper is coated with the coating layer using rollers, nozzles, blades, or scrapers, and then dried using IR radiators, hot air, or cylinder contact. An optical solution containing the optical brightener is applied to the dried coating layer and optionally dried again.

1. Field of the Invention
The invention relates to a coated, optically brightened printing paper and to a process for its production.
2. Description of the Related Arts
Coated, optically brightened printing papers are known per se and find manifold use in higher-quality printed products, such as illustrated books, brochures and company reports. Optical brighteners are likewise known. In addition to their main field of use in the detergent industry, they have also already been used for decades in the paper industry in order to increase the brightness of the paper produced. Viewed chemically, optical brighteners are derivatives of diaminostilbene disulfonic acid. Their effect is based on the absorption of UV light in a wavelength range from 300-400 nm and emission in a blue range of visible light in the range from 400-450 nm. This leads to a shift in the yellow cast of fibers and fillers into the blue-white range and ultimately to an increase in the spectral reflectance.
The use of optical brighteners during paper making can be carried out in various ways. During the production of coated printing papers, it can be added into the fibers stock suspension upstream of the flow box of the paper machine. If the paper machine has a size press, as it is known, for the surface treatment of the paper, the optical brightener can for example be metered into the starch solution used there. A third possibility is to meter the optical brightener into a coating color which is applied to the coating base paper inside or outside the paper machine or is possibly applied to an already pre-coated coating base paper.
In Wochenblatt fxc3xcr Papierfabrikation No. 15, pp. 529-534 (1983), a report is given on the size-press application of optical brighteners together with a starch suspension. It has also already been proposed to divide the amount of optical brightener to base paper, size press and coating, see PTS-Vortragsband 02/91, pp. 172-175, 15th Coating Symposium 1991.
A device for applying size suspensions, in addition to the known size press, is disclosed by DE-A-34 17 487, which corresponds to U.S. Pat. No. 4,848,268, where a paper web guided around a roll is treated on the front side with coating color and on the rear side with liquid media.
EP-A-0 373 276 describes a process and an apparatus for the continuous spraying of additives onto a moving paper web.
Coated, optically brightened papers produced in accordance with the prior art exhibit certain disadvantages. If the optical brightener is added to the fibers stock suspension upstream of the flow box or is applied to the surface of the coating base paper by means of a size press, then attenuation of the UV light and of the reflected blue light occurs as a result of the coating layer subsequently applied, so that the action of the optical brightener occurs only to an inadequate extent. Increasing the amount of additive is ruled out for cost reasons. Adding the optical brightener into the coating color to be applied is certainly possible in principle, but requires the addition of carrier substances, as they arm known, since the optical brightener itself does not adhere to the pigments of the coating color and therefore, to some extent, is absorbed into the base paper together with the water from the coating color. This problem was solved by the addition of carrier substances, as they are known. These are, for example, starches CMC and polyvinyl alcohol. Because of their anionic charge, they are capable of holding the cationically charged optical brighteners in the applied layer of coating color and bringing them into action under the influence of light.
However, the drawback with using carrier substances is their relatively high inherent viscosity in aqueous solution, which is added to the already relatively high viscosity of the coating color used.
This leads to viscosity problems when processing at high operating speeds in blade coating machines, said problems either limiting the operating speed, leading to non-uniform coating application or making it necessary to dilute the coating color, which in turn entails problems with the drying capacity of the drying equipment arranged downstream.
The object of the present invention is to provide a coated, optically brightened printing paper and a process for its production which overcomes the problems listed above.
In order to solve the problem, an optically brightened printing paper coated on one or both sides and coated once or many times is proposed, which comprises a coating base paper and a coating layer applied thereto and comprising pigment, binder and coating color aids, which is characterized in that the optical brightener is arranged on the outer side of a coating layer.
Printing paper coated on one side is understood to mean those papas which are provided only for single-sided printing. These include, for example, label papers for bottles and can wrappers. In the same sense, printing pap coated on both sides are printed on both sides. These include, for example, magazine papers, as they are known, for illustrated magazines or catalogues, but also art papers. High-value printed products require the highest surface quality of the side to be printed. This can no longer be achieved with a single coat, as it is known. For this reason, the coating base paper is firstly coated with one or two pre-coats, as they are known, and the top coat, as it is known, is arranged on them.
The pigments considered for the coating layer are all familiar coating pigments, such kaolin, calcium carbonate, talc, titanium dioxide, gypsum, etc.
The binders considered for the coating layer are likewise all familiar coating color binders, such as starch, protein, casein, synthetic lattices etc. Likewise, the coating layer contains conventional coating color aids, such as defoamer, deaerator, lubricant and viscosity regulator. Pigments, binders and coating color aids are familiar to those skilled in the art and active in this field.
The arrangement of the optical brightener on the outer side of the coating layer states that said it is arranged both on the outer side of the coating layer and in the outer layer under the outer side. The porosity of the coating layer, which is always present, if appropriate even after a preceding calendering operation brings about this arrangement with the advantageous effect that the UV proportion of the light strikes the optical brightener without or only with slight attenuation and is emitted as visible blue light in the range from 400-450 nm without or with only slight attenuation as result of which the yellow cast of the fibers and pigments is shifted into the blue-white range. This ultimately leads to an increase in the spectral reflectance and to an improvement in the paper quality. With this arrangement of the optical brightener, a reduction in the amount of brightener is also possible, because of the improved efficiency, so that a reduction in costs is possible.
In a preferred embodiment of the optically brightened printing paper, the optical brightener is arranged on the outer side of the top coat of a coating layer consisting of one or more pre-coats and a top coat. This embodiment has the advantage that no excessively high demands have to be made on the brightness quality of the pre-coat pigments, since the lower brightness of these pigments is compensated for by the whitening effect on the outer layer of the top coat. A reduction in costs is therefore possible.
In a further embodiment of the optically brightened printing paper, the optical brightener is arranged on the outer side of a first coating layer and a further coating layer without an optical brightener is arranged over that. It is known that optical brighteners are destroyed by the continuous action of UV light, and the paper grays. On the other hand, however, in specific applications of the optically brightened printing paper it is not possible to avoid said paper being continually exposed to light. This occurs, for example, in the case of illuminated advertising placards. In this case, the optical brightener arranged on a first coating layer is protected against too much UV light by the further coating layer arranged above it without losing its whitening action.
A process according to the invention for producing an optically brightened printing paper coated on one or both sides and coated once or many times is characterized by the combination of the following features:
A coating base paper, containing chemical pulp and/or groundwood pulp and/or recycled fibers and/or fillers is coated with a coating color, containing white pigments, binders and coating color aids, in a manner known per se by means of roll, nozzle, roll doctor or blade doctor application. The coating applied is dried immediately thereafter by means of infrared radiators, hot air or cylinder contact. Here, a combination of the various drying systems with one another is also possible. An aqueous solution of a derivative of the diaminostilbene disulfonic acid is then applied to the dried top side of the coating layer and, if necessary, dried again.
In order to apply the aqueous solution, roll application devices known per se can be used. A further tried and tested application technique consists in a nozzle application of the aqueous solution. Nozzle applicators of this type are familiar to those skilled in the art.
A preferred embodiment of the process consists in the application of the aqueous solution being performed by means of a roll or nozzle moistener, as it is known, on one or both sides of the coated paper web, the solution or the derivative of the diaminostilbene disulfonic acid being added to the dampening water. This embodiment is recommended in particular when a moisture correction must be carried out on the coated paper web.
The application of the aqueous solution of the derivative of the diaminostilbene disulfonic acid can be carried out in the coating machine arranged directly downstream of the paper machine or in a separately operated coating machine. However, it is also possible to apply the aqueous solution to the calendered coating layer in a rewetting device arranged downstream of a calender, the solution of the derivative of the diaminostilbene disulfonic acid being added to the dampening water.
If the binder contained in the coating layer has carrier properties, such as starch, polyvinyl alcohol or CMC, then a purely aqueous solution of the derivative of the diaminostilbene disulfonic acid can be used for the application. However, if these carrier properties are lacking in the coating layer, then the aqueous solution has a water-soluble carrier, such as starch, CMC or polyvinyl alcohol, added to it. The required amount of optical brightener and, if appropriate, carrier can easily de determined themselves by those skilled in the art. An aqueous solution of 10% by weight of optical brightener (commercially available material) and 3% dissolved starch has been tried and tested.

Method for producing an enameled, optically brightened printing paper

Stora Enso Publication Paper GmbH and Co., KG


The present invention relates to the potentiation of glutamate receptor function using certain heterocyclic sulphonamide derivatives. It also relates to novel heterocyclic sulphonamide derivatives, to processes for their preparation and to pharmaceutical compositions containing them.

The present invention relates to the potentiation of glutamate receptor function using certain heterocyclic sulphonamide derivatives. It also relates to novel heterocyclic sulphonamide derivatives, to processes for their preparation and to pharmaceutical compositions containing them.
In the mammalian central nervous system (CNS), the transmission of nerve impulses is controlled by the interaction between a neurotransmitter, that is released by a sending neuron, and a surface receptor on a receiving neuron, which causes excitation of this receiving neuron. L-Glutamate, which is the most abundant neurotransmitter in the CNS, mediates the major excitatory pathway in mammals, and is referred to as an excitatory amino acid (EAA). The receptors that respond to glutamate are called excitatory amino acid receptors (EAA receptors). See Watkins and Evans, Ann. Rev. Pharmacol. Toxicol., 21, 165 (1981); Monaghan, Bridges, and Cotman, Ann. Rev. Pharmacol. Toxicol., 29, 365 (1989); Watkins, Krogsgaard-Larsen, and Honore, Trans. Pharm. Sci., 11, 25 (1990). The excitatory amino acids are of great physiological importance, playing a role in a variety of physiological processes, such as long-term potentiation (learning and memory), the development of synaptic plasticity, motor control, respiration, cardiovascular regulation, and sensory perception.
Excitatory amino acid receptors are classified into two general types. Receptors that are directly coupled to the opening of cation channels in the cell membrane of the neurons are termed xe2x80x9cionotropicxe2x80x9d. This type of receptor has been subdivided into at least three subtypes, which are defined by the depolarizing actions of the selective agonists N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), and kainic acid (KA). The second general type of receptor is the G-protein or second messenger-linked xe2x80x9cmetabotropicxe2x80x9d excitatory amino acid receptor. This second type is coupled to multiple second messenger systems that lead to enhanced phosphoinositide hydrolysis, activation of phospholipase D, increases or decreases in c-AMP formation, and changes in ion channel function. Schoepp and Conn, Trends in Pharmacol. Sci., 14, 13 (1993). Both types of receptors appear not only to mediate normal synaptic transmission along excitatory pathways, but also participate in the modification of synaptic connections during development and throughout life. Schoepp, Bockaert, and Sladeczek, Trends in Pharmacol. Sci., 11, 508 (1990); McDonald and Johnson, Brain Research Reviews, 15, 41 (1990).
AMPA receptors are assembled from four protein sub-units known as GluR1 to GluR4, while kainic acid receptors are assembled from the sub-units GluR5 to GluR7, and KA-1 and KA-2. Wong and Mayer, Molecular Pharmacology 44: 505-510, 1993. It is not yet known how these sub-units are combined in the natural state. However, the structures of certain human variants of each sub-unit have been elucidated, and cell lines expressing individual sub-unit variants have been cloned and incorporated into test systems designed to identify compounds which bind to or interact with them, and hence which may modulate their function. Thus, European patent application, publication number EP-A2-0574257 discloses the human sub-unit variants GluR1B, GluR2B, GluR3A and GluR3B. European patent application, publication number EP-A1-0583917 discloses the human sub-unit variant GluR4B.
One distinctive property of AMPA and kainic acid receptors is their rapid deactivation and desensitization to glutamate. Yamada and Tang, The Journal of Neuroscience, September 1993, 13(9): 3904-3915 and Kathryn M. Partin, J. Neuroscience, Nov. 1, 1996, 16(21): 6634-6647. The physiological implications of rapid desensitization, and deactivation if any, are unknown.
It is known that the rapid desensitization and deactivation of AMPA and/or kainic acid receptors to glutamate may be inhibited using certain compounds. This action of these compounds is often referred to in the alternative as xe2x80x9cpotentiationxe2x80x9d of the receptors. One such compound, which selectively potentiates AMPA receptor function, is cyclothiazide. Partin et al., Neuron. Vol. 11, 1069-1082, 1993. Compounds which potentiate AMPA receptors, like cyclothiazide, are often referred to as ampakines.
International Patent Application Publication Number WO 9625926 discloses a group of phenylthioalkylsulphonamides, S-oxides and homologs which are said to potentiate membrane currents induced by kainic acid and AMPA.
Ampakines have been shown to improve memory in a variety of animal tests. Staubli et al., Proc. Natl. Acad. Sci., Vol. 91, pp 777-781, 1994, Neurobiology, and Arai et al., The Journal of Pharmacology and Experimental Therapeutics, 278: 627-638, 1996.
It has now been found that cyclothiazide and certain heterocyclic sulphonamide derivatives potentiate agonist-induced excitability of human GluR4B receptor expressed in HEK 293 cells. Since cyclothiazide is known to potentiate glutamate receptor function in vivo, it is believed that this finding portends that the heterocyclic sulphonamide derivatives will also potentiate glutamate receptor function in vivo, and hence that the compounds will exhibit ampakine-like behavior.
Accordingly, the present invention provides a compound of the formula:
wherein:
R1a represents hydrogen or (1-4C)alkyl;
R1b and R1c together with the carbon atom to which they are attached form a 4 to 7 membered saturated heterocyclic ring containing as the hetero ring members a group NRa and a group X, wherein X is selected from the group consisting of xe2x80x94CH2xe2x80x94, xe2x80x94NRbxe2x80x94, xe2x80x94Oxe2x80x94 and xe2x80x94Sxe2x80x94; and
Ra represents hydrogen, (1-4C)alkyl, optionally substituted aryl or optionally substituted aryl(1-4C)alkyl;
Rb represents hydrogen, (1-4C)alkyl, optionally =substituted aryl or optionally substituted aryl(1-4C)alkyl;
R2 represents (1-6C)alkyl, (3-6C)cycloalkyl, (1-6C)fluoroalkyl, (1-6C)chloroalkyl, (2-6C)alkenyl, (1-4C)alkoxy(1-4C)alkyl, phenyl which is unsubstituted or substituted by halogen, (1-4C)alkyl or (1-4C)alkoxy, or a group of formula R3R4N in which R3 and R4 each independently represents (1-4C)alkyl or, together with the nitrogen atom to which they are attached form an azetidinyl, pyrrolidinyl, piperidinyl, morpholino, piperazinyl, hexahydroazepinyl or octahydroazocinyl group; and
either (a) one or two of R5, R6, R7 and R8 represents hydrogen; (1-6C)alkyl; aryl(1-6C)alkyl; (2-6C)alkenyl; aryl(2-6C)alkenyl or aryl, or (b) two of R5, R6, R7 and R8 together with the carbon atom or carbon atoms to which they are attached form a (3-8C) carbocyclic ring; and the remainder of R5, R6, R7 and R8 represent hydrogen; or a pharmaceutically acceptable salt thereof.
According to another aspect, the present invention provides a method of potentiating glutamate receptor function in a mammal requiring such treatment, which comprises administering an effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof as defined herein.
According to another aspect, the present invention provides the use of a compound of formula I, or a pharmaceutically acceptable salt thereof as defined herein for the manufacture of a medicament for potentiating glutamate receptor function.
According to yet another aspect, the present invention provides the use of a compound of formula I or a pharmaceutically acceptable salt thereof as defined herein for potentiating glutamate receptor function.
In this specification, the term xe2x80x9cpotentiating glutamate receptor functionxe2x80x9d refers to any increased responsiveness of glutamate receptors, for example AMPA receptors, to glutamate or an agonist, and includes but is not limited to inhibition of rapid desensitisation or deactivation of AMPA receptors to glutamate.
A wide variety of conditions may be treated by the compounds of formula I and their pharmaceutically acceptable salts through their action as potentiators of glutamate receptor function. Such conditions include those associated with glutamate hypofunction, such as psychiatric and neurological disorders, for example cognitive disorders; neuro-degenerative disorders such as Alzheimer""s disease; age-related dementias; age-induced memory impairment; movement disorders such as tardive dyskinesia, Hungtington""s chorea, myoclonus and Parkinson""s disease; reversal of drug-induced states (such as cocaine, amphetamines, alcohol-induced states); depression; attention deficit disorder; attention deficit hyperactivity disorder; psychosis; cognitive deficits associated with psychosis; and drug-induced psychosis. The compounds of formula I may also be useful for improving memory (both short term and long term) and learning ability. The present invention provides the use of compounds of formula I for the treatment of each of these conditions.
The term xe2x80x9ctreatingxe2x80x9d (or xe2x80x9ctreatxe2x80x9d) as used herein includes its generally accepted meaning which encompasses prohibiting, preventing, restraining, and slowing, stopping, or reversing progression, severity, or a resultant symptom.
The present invention includes the pharmaceutically acceptable salts of the compounds defined by formula I. A compound of this invention can possess a sufficiently acidic, a sufficiently basic, or both functional groups, and accordingly react with any of a number of organic and inorganic bases, and inorganic and organic acids, to form a pharmaceutically acceptable salt.
The term xe2x80x9cpharmaceutically acceptable saltxe2x80x9d as used herein, refers to salts of the compounds of the above formula which are substantially non-toxic to living organisms. Typical pharmaceutically acceptable salts include those salts prepared by reaction of the compounds of the present invention with a pharmaceutically acceptable mineral or organic acid or an organic or inorganic base. Such salts are known as acid addition and base addition salts.
Acids commonly employed to form acid addition salts are inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, phosphoric acid, and the like, and organic acids such as p-toluenesulfonic, methanesulfonic acid, oxalic acid, p-bromophenylsulfonic acid, carbonic acid, succinic acid, citric acid, benzoic acid, acetic acid, and the like. Examples of such pharmaceutically acceptable salts are the sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, propionate, decanoate, caprylate, acrylate, formate, hydrochloride, dihydrochloride, isobutyrate, caproate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, fumarate, maleate, butyne-1,4-dioate, hexyne-1,6-dioate, benzoate, chlorobenzoate, methylbenzoate, hydroxybenzoate, methoxybenzoate, phthalate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, xcex3-hydroxybutyrate, glycolate, tartrate, methanesulfonate, propanesulfonate, naphthalene-l-sulfonate, napththalene-2-sulfonate, mandelate and the like. Preferred pharmaceutically acceptable acid addition salts are those formed with mineral acids such as hydrochloric acid and hydrobromic acid, and those formed with organic acids such as maleic acid and methanesulfonic acid.
Base addition salts include those derived from inorganic bases, such as ammonium or alkali or alkaline earth metal hydroxides, carbonates, bicarbonates, and the like. Such bases useful in preparing the salts of this invention thus include sodium hydroxide, potassium hydroxide, ammonium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, calcium hydroxide, calcium carbonate, and the like. The potassium and sodium salt forms are particularly preferred.
It should be recognized that the particular counterion forming a part of any salt of this invention is usually not of a critical nature, so long as the salt as a whole is pharmacologically acceptable and as long as the counterion does not contribute undesired qualities to the salt as a whole. It is further understood that the above salts may form hydrates or exist in a substantially anhydrous form.
As used herein, the term xe2x80x9cstereoisomerxe2x80x9d refers to a compound made up of the same atoms bonded by the same bonds but having different three-dimensional structures which are not interchangeable. The three-dimensional structures are called configurations. As used herein, the term xe2x80x9cenantiomerxe2x80x9d refers to two stereoisomers whose molecules are nonsuperimposable mirror images of one another. The term xe2x80x9cchiral centerxe2x80x9d refers to a carbon atom to which four different groups are attached. As used herein, the term xe2x80x9cdiastereomersxe2x80x9d refers to stereoisomers which are not enantiomers. In addition, two diastereomers which have a different configuration at only one chiral center are referred to herein as xe2x80x9cepimersxe2x80x9d. The terms xe2x80x9cracematexe2x80x9d, xe2x80x9cracemic mixturexe2x80x9d or xe2x80x9cracemic modificationxe2x80x9d refer to a mixture of equal parts of enantiomers.
The term xe2x80x9cenantiomeric enrichmentxe2x80x9d as used herein refers to the increase in the amount of one enantiomer as compared to the other. A convenient method of expressing the enantiomeric enrichment achieved is the concept of enantiomeric excess, or xe2x80x9ceexe2x80x9d, which is found using the following equation:   ee  =                              E          1                -                  E          2                                      E          1                +                  E          2                      xc3x97    100
wherein E1 is the amount of the first enantiomer and E2 is the amount of the second enantiomer. Thus, if the initial ratio of the two enantiomers is 50:50, such as is present in a racemic mixture, and an enantiomeric enrichment sufficient to produce a final ratio of 50:30 is achieved, the ee with respect to the first enantiomer is 25%. However, if the final ratio is 90:10, the ee with respect to the first enantiomer is 80%. An ee of greater than 90% is preferred, an ee of greater than 95% is most preferred and an ee of greater than 99% is most especially preferred. Enantiomeric enrichment is readily determined by one of ordinary skill in the art using standard techniques and procedures, such as gas or high performance liquid chromatography with a chiral column. Choice of the appropriate chiral column, eluent and conditions necessary to effect separation of the enantiomeric pair is well within the knowledge of one of ordinary skill in the art. In addition, the enantiomers of compounds of formula I can be resolved by one of ordinary skill in the art using standard techniques well known in the art, such as those described by J. Jacques, et al., xe2x80x9cEnantiomers, Racemates, and Resolutionsxe2x80x9d, John Wiley and Sons, Inc., 1981. Examples of resolutions include recrystallization techniques or chiral chromatography.
Some of the compounds of the present invention have one or more chiral centers and may exist in a variety of stereoisomeric configurations. As a consequence of these chiral centers, the compounds of the present invention occur as racemates, mixtures of enantiomers and as individual enantiomers, as well as diastereomers and mixtures of diastereomers. All such racemates, enantiomers, and diastereomers are within the scope of the present invention.
The terms xe2x80x9cRxe2x80x9d and xe2x80x9cSxe2x80x9d are used herein as commonly used in organic chemistry to denote specific configuration of a chiral center. The term xe2x80x9cRxe2x80x9d (rectus) refers to that configuration of a chiral center with a clockwise relationship of group priorities (highest to second lowest) when viewed along the bond toward the lowest priority group. The term xe2x80x9cSxe2x80x9d (sinister) refers to that configuration of a chiral center with a counterclockwise relationship of group priorities (highest to second lowest) when viewed along the bond toward the lowest priority group. The priority of groups is based upon their atomic number (in order of decreasing atomic number). A partial list of priorities and a discussion of stereochemistry is contained in xe2x80x9cNomenclature of Organic Compounds: Principles and Practicexe2x80x9d, (J. H. Fletcher, et al., eds., 1974) at pages 103-120.
As used herein, the term xe2x80x9carylxe2x80x9d includes phenyl and a polycyclic aromatic carbocyclic ring such as naphthyl.
The term xe2x80x9coptionally substitutedxe2x80x9d as used in the term xe2x80x9coptionally substituted arylxe2x80x9d or xe2x80x9coptionally substituted aryl(1-4C)alkylxe2x80x9d herein signifies that the aryl group is unsubstituted or substituted by one or more (for example one or two) substituents, said substituents being selected from atoms and groups which, when present in the compound of formula I, do not prevent the compound of formula I from functioning as a potentiator of glutamate receptor function.
Examples of substituents which may be present in an optionally substituted aryl group include halogen; nitro; cyano; (1-4C)alkyl; (1-4C)alkoxy; halo(1-4C)alkyl; and a group of formula xe2x80x94(L1)xxe2x80x94X1xe2x80x94(L2)yxe2x80x94R9 in which each of L1 and L2 independently represents (1-4C)alkylene, one of x and y is 0 and the other is 0 or 1, X1 represents a bond, O, S, NH, CO, CONH or NHCO, and R9 represents a phenyl group that is unsubstituted or substituted by one or two of halogen, (1-4C)alkyl and (1-4C)haloalkyl.
Unless specified otherwise, any alkyl group may be unbranched or branched. The term xe2x80x9c(1-6C)alkylxe2x80x9d includes xe2x80x9c(1-4C)alkylxe2x80x9d. Examples of particular values for a (1-6C)alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl and hexyl.
The term (1-4C)alkylene includes (2-4C)alkylene. Examples of particular values are methylene and ethylene.
The 4 to 7 membered saturated heterocyclic ring containing a group NRa and a group X, wherein X is selected from the group consisting of xe2x80x94CH2xe2x80x94, xe2x80x94NRbxe2x80x94, xe2x80x94Oxe2x80x94 and xe2x80x94Sxe2x80x94 may be selected, for example, from azetidinyl, pyrrolidinyl, piperidinyl, morpholinyl, thiomorpholinyl, piperazinyl, hexahydropyrimidyl, tetrahydro-1,3-oxazinyl, tetrahydro-1,3-thiazinyl and hexahydroazepinyl.
Examples of 4 to 7 membered saturated heterocyclic rings are those wherein R1b and R1c together with the carbon atom to which they are attached are selected from the group consisting of:
wherein Ra represents hydrogen, (1-4C)alkyl, optionally substituted aryl or optionally substituted aryl(1-4C)alkyl; and Rb represents hydrogen, (1-4C)alkyl, optionally substituted aryl or optionally substituted aryl(1-4C)alkyl.
Examples of particular values for Ra and Rb are methyl, ethyl, propyl, phenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2,3-difluorophenyl, 2,4-difluorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 4-cyanophenyl, 3-nitrophenyl, 2-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 3-propylphenyl, 4-t-butylphenyl, 2-trifluoromethylphenyl, 3-trifluoromethylphenyl, 4-trifluoromethylphenyl, 2-fluoro-4-trifluoromethylphenyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl and benzyl.
A preferred value for the 4 to 7 membered saturated heterocyclic ring is a group of formula (a) above, such as N-methyl-2-pyrrolidinyl, or a group of formula (e) above, such as 1-(2-fluorophenyl)piperidin-4-yl.
An alkenyl group, for example as in (2-6C)alkenyl or aryl(2-6C)alkenyl may be branched or unbranched. Examples of particular values are vinyl and prop-2-enyl.
The term (3-8C)cycloalkyl includes (3-6C)cycloalkyl. Examples of particular values for (3-8C)cycloalkyl are cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.
The term xe2x80x9chalo(1-6C)alkylxe2x80x9d includes halo(1-4C)alkyl, (1-6C)fluoroalkyl, such as trifluoromethyl or 2,2,2-trifluoroethyl, and (1-6C)chloroalkyl, such as chloromethyl.
The term xe2x80x9chalogenxe2x80x9d includes fluorine, chlorine and bromine.
An example of a particular value for R1a is hydrogen.
Examples of values for R2 are methyl, ethyl, propyl, 2-propyl, butyl, 2-methylpropyl, cyclohexyl, trifluoromethyl, 2,2,2-trifluoroethyl, chloromethyl, ethenyl, prop-2-enyl, methoxyethyl, phenyl, 4-fluorophenyl, or dimethylamino.
Preferably R2 is ethyl, 2-propyl or dimethylamino.
Preferably R3 and R4 each represent methyl.
Examples of a (1-6C)alkyl group represented by R5, R6, R7 and R8 are methyl, ethyl and propyl. An example of an aryl(1-C)alkyl group is benzyl. An example of a (2-6C)alkenyl group is prop-2-enyl. An example of a (3-8C)carbocyclic ring is a cyclopropyl ring.
Preferably R6 and R7 each represents hydrogen.
Preferably R5 and R8 each independently represents hydrogen or (1-4C)alkyl, or together with the carbon atom to which they are attached form a (3-8C) carbocyclic ring.
More preferably R8 represents methyl or ethyl and R5 represents hydrogen or methyl, or R5 and R8 together with the carbon atom to which they are attached form a cyclopropyl ring.
Especially preferred are compounds in which R8 represents methyl and R5, R6 and R7 each represents hydrogen.
The compounds of formula I may be prepared by reacting a compound of formula
with a compound of formula
R2SO2Zxe2x80x83xe2x80x83III
in which Z represents a leaving atom or group, followed where necessary and/or desired by forming a pharmaceutically acceptable salt.
The leaving atom or group represented by Z may be, for is example, a halogen atom such as a chlorine or bromine atom.
The reaction is conveniently performed in the presence of a base, for example an alkali metal hydroxide such as sodium hydroxide, an alkali metal carbonate such as potassium carbonate, a tertiary amine such as triethylamine or 1,8-diazabicyclo[5.4.0]undec-7-ene.
Suitable solvents include halogenated hydrocarbons such as dichloromethane.
The reaction is conveniently performed at a temperature in the range of from xe2x88x9220 to 100xc2x0 C., preferably from xe2x88x925 to 50xc2x0 C.
The compounds of formula II are known or may be prepared by reducing a corresponding nitrile or amide, for example using a borane, such as borane dimethyl sulfide, or lithium aluminium hydride. Convenient solvents for the reduction include ethers, such as tetrahydrofuran and diethyl ether.
Some of the nitriles and amides used as starting materials may conveniently be prepared by treatment of a nitrile of formula
or an ester of formula
in which is an ester residue, such as a (1-6C)alkyl group, with a strong base, for example an alkali metal amide such as sodium or lithium bis(trimethylsilyl)amide and a compound of formula R5Z1 or R8Z1 in which Z1 represents a leaving atom or group, such as an iodine atom. Convenient solvents include ethers, such as tetrahydrofuran. The temperature is conveniently in the range of from xe2x88x9278 to 25xc2x0 C. The esters are then converted to the amides by hydrolysis, for example using sodium or potassium hydroxide in an aqueous alcohol to afford an acid, and conversion of the acid to an amide, for example by reaction of the acid with thionyl chloride followed by aqueous ammonia.
Alternatively, a compound of formula
may be reacted with toluenesulfonylmethyl isocyanide in the presence of a strong base, such as potassium t-butoxide. Suitable solvents include ethyleneglycol dimethyl ether (DME). The reaction is conveniently performed at a temperature in the range of from xe2x88x9278 to 25xc2x0 C.
It will be appreciated that in the processes described above, it may be preferable to protect the nitrogen atom in the groups represented by NRa and NRb when Ra or Rb is hydrogen. Suitable protecting groups include acyl groups, such as acetyl or benzoyl, and acyloxy groups, such as t-butoxycarbonyl. A t-butoxycarbonyl may conveniently be removed using trifluoroacetic acid.
The ability of compounds of formula I to potentiate glutamate receptor-mediated response may be determined using fluorescent calcium indicator dyes (Molecular Probes, Eugene, Oreg., Fluo-3) and by measuring glutamate-evoked efflux of calcium into GluR4 transfected HEK293 cells, as described in more detail below.
In one test, 96 well plates containing confluent monolayers of HEK cells stably expressing human GluR4B (obtained as described in European Patent Application Publication Number EP-A1-583917) are prepared. The tissue culture medium in the wells is then discarded, and the wells are each washed once with 200 xcexcl of buffer (glucose, 10 mM, sodium chloride, 138 mM, magnesium chloride, 1 mM, potassium chloride, 5 mM, calcium chloride, 5 mM, N-[2-hydroxyethyl]-piperazine-N-[2-ethanesulfonic acid], 10 mM, to pH 7.1 to 7.3). The plates are then incubated for 60 minutes in the dark with 20 xcexcM Fluo3-AM dye (obtained from Molecular Probes Inc, Eugene, Oreg.) in buffer in each well. After the incubation, each well is washed once with 100 xcexcl buffer, 200 xcexcl of buffer is added and the plates are incubated for 30 minutes.
Solutions for use in the test are also prepared as follows. 30 xcexcM, 10 xcexcM, 3 xcexcM and 1 xcexcM dilutions of test compound are prepared using buffer from a 10 mM solution of test compound in DMSO. 100 xcexcM cyclothiazide solution is prepared by adding 3 xcexcl of 100 mM cyclothiazide to 3 ml of buffer. Control buffer solution is prepared by adding 1.5 xcexcl DMSO to 498.5 xcexcl of buffer.
Each test is then performed as follows. 200 xcexcl of control buffer in each well is discarded and replaced with 45 xcexcl of control buffer solution. A baseline fluorescent measurement is taken using a FLUOROSKAN II fluorimeter (Obtained from Labsystems, Needham Heights, Mass., USA, a Division of Life Sciences International Plc). The buffer is then removed and replaced with 45 xcexcl of buffer and 45 xcexcl of test compound in buffer in appropriate wells. A second fluorescent reading is taken after 5 minutes incubation. 15 xcexcl of 400 xcexcM glutamate solution is then added to each well (final glutamate concentration 100 xcexcM), and a third reading is taken. The activities of test compounds and cyclothiazide solutions are determined by subtracting the second from the third reading (fluorescence due to addition of glutamate in the presence or absence of test compound or cyclothiazide) and are expressed relative to enhance fluorescence produced by 100 xcexcM cyclothiazide.
In another test, HEK293 cells stably expressing human GluR4 (obtained as described in European Patent Application Publication No. EP-A1-0583917) are used in the electro-physiological characterization of AMPA receptor potentiators. The extracellular recording solution contains (in mM): 140 NaCl, 5 KCl, 10 HEPES, 1 MgCl2, 2 CaCl2, 10 glucose, pH=7.4 with NaOH, 295 mOsm kgxe2x88x921. The intracellular recording solution contains (in M): 140 CsCl, 1 MgCl2, 10 HEPES, (N-[2-hydroxyethyl]piperazine-N1-[2-ethanesulfonic acid]) 10 EGTA (ethylene-bis(oxyethylenenitrilo)tetraacetic acid), pH=7.2 with CsOH, 295 mOsm kgxe2x88x921. With these solutions, recording pipettes have a resistance of 2-3 Mxcexa9. Using the whole-cell voltage clamp technique (Hamill et al.(1981)Pflxc3xcgers Arch., 391: 85-100), cells are voltage-clamped at xe2x88x9260 mV and control current responses to 1 mM glutamate are evoked. Responses to 1 mM glutamate are then determined in the presence of test compound. Compounds are deemed active in this test if, at a test concentration of 10 xcexcM, they produce a greater than 30% increase in the value of the current evoked by 1 mM glutamate.
In order to determine the potency of test compounds, the concentration of the test compound, both in the bathing solution and co-applied with glutamate, is increased in half log units until the maximum effect was seen. Data collected in this manner are fit to the Hill equation, yielding an EC50 value, indicative of the potency of the test compound. Reversibility of test compound activity is determined by assessing control glutamate 1 mM responses. Once the control responses to the glutamate challenge are re-established, the potentiation of these responses by 100 xcexcM cyclothiazide is determined by its inclusion in both the bathing solution and the glutamate-containing solution. In this manner, the efficacy of the test compound relative to that of cyclothiazide can be determined.
According to another aspect, the present invention provides a pharmaceutical composition, which comprises a compound of formula I or a pharmaceutically acceptable salt thereof as defined hereinabove and a pharmaceutically acceptable diluent or carrier.
The pharmaceutical compositions are prepared by known procedures using well-known and readily available ingredients. In making the compositions of the present invention, the active ingredient will usually be mixed with a carrier, or diluted by a carrier, or enclosed within a carrier, and may be in the form of a capsule, sachet, paper, or other container. When the carrier serves as a diluent, it may be a solid, semi-solid, or liquid material which acts as a vehicle, excipient, or medium for the active ingredient. The compositions can be in the form of tablets, pills, powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups, aerosols, ointments containing, for example, up to 10% by weight of active compound, soft and hard gelatin capsules, suppositories, sterile injectable solutions, and sterile packaged powders.
Some examples of suitable carriers, excipients, and diluents include lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum, acacia, calcium phosphate, alginates, tragcanth, gelatin, calcium silicate, micro-crystalline cellulose, polyvinylpyrrolidone, cellulose, water syrup, methyl cellulose, methyl and propyl hydroxybenzoates, talc, magnesium stearate, and mineral oil. The formulations can additionally include lubricating agents, wetting agents, emulsifying and suspending agents, preserving agents, sweetening agents, or flavoring agents. Compositions of the invention may be formulated so as to provide quick, sustained, or delayed release of the active ingredient after administration to the patient by employing procedures well known in the art.
The compositions are preferably formulated in a unit dosage form, each dosage containing from about 1 mg to about 500 mg, more preferably about 5 mg to about 300 mg (for example 25 mg) of the active ingredient. The term xe2x80x9cunit dosage formxe2x80x9d refers to a physically discrete unit suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical carrier, diluent, or excipient. The following formulation examples are illustrative only and are not intended to limit the scope of the invention in any way.
Hard gelatin capsules are prepared using the following ingredients:
The above ingredients are mixed and filled into hard gelatin capsules in 460 mg quantities.
Tablets each containing 60 mg of active ingredient are made as follows:
The active ingredient, starch, and cellulose are passed through a No. 45 mesh U.S. sieve and mixed thoroughly. The solution of polyvinylpyrrolidone is mixed with the resultant powders which are then passed through a No. 14 mesh U.S. sieve. The granules so produced are dried at 50xc2x0 C. and passed through a No. 18 mesh U.S. sieve. The sodium carboxymethyl starch, magnesium stearate, and talc, previously passed through a No. 60 mesh U.S. sieve, are then added to the granules which, after mixing, are compressed on a tablet machine to yield tablets each weighing 150 mg.
As used herein the term xe2x80x9cpatientxe2x80x9d refers to a mammal, such as a mouse, guinea pig, rat, dog or human. It is understood that the preferred patient is a human.
As used herein the term xe2x80x9ceffective amountxe2x80x9d refers to the amount or dose of the compound which provides the desired effect in the patient under diagnosis or treatment.
The particular dose of compound administered according to this invention will of course be determined by the particular circumstances surrounding the case, including the compound administered, the route of administration, the particular condition being treated, and similar considerations. The compounds can be administered by a variety of routes including oral, rectal, transdermal, subcutaneous, intravenous, intramuscular, or intranasal routes. Alternatively, the compound may be administered by continuous infusion. A typical daily dose will contain from about 0.01 mg/kg to about 100 mg/kg of the active compound of this invention. Preferably, daily doses will be about 0.05 mg/kg to about 50 mg/kg, more preferably from about 0.1 mg/kg to about 25 mg/kg.


The present invention provides a pharmaceutical combination preparation comprising an erythropoietin preparation that provides active erythropoietin and at least one modified haemoglobin wherein the erythropoietin preparation and modified haemoglobin can be present in separate forms of administration or in a single form of administration. The pharmaceutical combination preparations of the present invention can be used to treat manifest anemias with or without iron utilization disorders.

The invention is concerned with pharmaceutical combination preparations containing erythropoietin preparations and one or more modified haemoglobins. The combination preparations are especially useful for the treatment of manifest anaemias.
The object of the present invention is a pharmaceutical combination preparation which comprises a) individual administration forms of an erythropoietin preparation suitable for the individual dosing of the active substance in an amount of 3,000-7,000 U and b) 50-100 ml of one or more modified haemoglobins, with the erythropoietin preparation and modified haemoglobin being present in separate administration forms or in a single administration form.
The macromolecule ferritin (molecular weight at least 440 kD depending on the iron content) plays a significant role in the diagnosis of anaemias. An estimation of the fullness level of the iron reservoir is possible by determining the ferritin and the transferrin saturation (M.Wick, W. Pingerra, P. Lehmann xe2x80x9cFerritin in iron metabolism and diagnosis of anaemiasxe2x80x9d, pages 5-22, 38-50, 65-77, 94-97, 2nd expanded edition 1994, published by Springer Vienna, New York), with the totality of the iron stored as basic ferritin in the depot organs liver, spleen and bone marrow amounting to about 800-1200 mg. A lower ferritin concentration is the definitive characteristic for detecting iron deficiency states and their difference from other causes of hypochromic anaemia, such as e.g. chronic inflammations and tumours.
It is known to treat transfusion-mediated anaemias in haemodialysis patients with recombinant erythropoietin (rhEPO), with it being necessary as a rule to carry out an iron substitution in parallel to the EPO therapy. This iron substitution is effected by the intravenous administration of iron(III) salts, with two intravenously administerable iron preparations being available on the German medicament market at present. These are the medicaments xe2x80x9cFerrlecitxe2x80x9d and xe2x80x9cFerrum Vitesxe2x80x9d. xe2x80x9cFerrlecitxe2x80x9d is an iron(III) gluconate complex, while xe2x80x9cFerrum Vitesxe2x80x9d is an iron(III) oxide saccharate complex.
It has, however, become evident that in the case of manifest anaemias with manifest iron deficiency and iron utilization disorders ( less than 30 mg/dl ferritin) iron substitution with the mentioned preparations has disadvantages, since for the treatment of manifest anaemias relatively large amounts of a pharmacologically harmless iron salt have to be infused. The use of the aforementioned iron preparations holds the possibility of unexpected circulatory reactions up to collapse, especially when large amounts have to be injected relatively rapidly.
In WO 96/15805 there is described a haemoglobin therapy for haemodialysis according to which very low doses of stroma-free haemoglobin are administered over a period of 10 to 45 minutes in order to achieve a haemostabilization and to avoid a lowering of blood pressure in sensitive patients. However, this described therapy is not successful in the case of manifest iron deficiency anaemias.
Also, WO 95/24213 describes the use of natural or recombinant haemoglobin or their chemically modified derivatives for anaemia treatment. Furthermore, this document discloses the combined administration of one of the aforementioned haemoglobins with one or more haematopoietic growth factors, inter alia with EPO. Examples 4 and 5 as well as some of the Figures show that a combined administration of EPO and rh haemoglobin lead to an increased haematopoesis.
However, this document does not disclose a practical therapeutic regime for an optimal regulation and treatment of patients with manifest anaemias. Also, it is not evident therefrom, as in the case of patients treated with EPO, that it is possible to produce an optimal EPO effect without avoiding an EPO resistance.
It has now been found that the use of relatively high infusion amounts of 50-100 ml of haemoglobin (about 100-200 mg Fe2+) together with 3,000-7,000 U of EPO is surprisingly advantageous for the treatment of manifest anaemias (the abbreviation xe2x80x9cIUxe2x80x9d can also be used in place of the abbreviation xe2x80x9cUxe2x80x9d for International Units).
The object of the invention are accordingly also combination preparations which contain 3,000-7,000 U of EPO and 50-100 ml of one or more modified haemoglobins, with the EPO and the modified haemoglobin being present in separate administration forms or in a single administration form.
In accordance with the invention 3,000-7,000 U of an erythropoietin preparation and 50-100 ml of one or more modified haemoglobins are used as the optimal dose depending on the clinical picture of the anaemia. Thus, in the case of manifest anaemias without iron distribution disorders, a high dose of Fe2+, about 80-100 ml (about 160-200 mg Fe2+), preferably 85-95 ml, in the form of a modified haemoglobin and a lower dose of EPO between 3,000 and 5,000 U is administered in accordance with the invention.
When there are iron distribution disorders in the case of manifest anaemias, a higher EPO dose of about 5,000-7,000 U of EPO, preferably 6,000-7,000 U, especially about 7,000 U of EPO, and a high Fe2+ dose, about 80-100 ml, preferably about 100 ml, in the form of one or more modified haemoglobins is preferably administered.
For the treatment of iron utilization disorders in the case of manifest anaemias the combination preparation in accordance with the invention preferably contains 3,000-7,000 U of EPO and 80-100 ml of a modified haemoglobin, preferably about 5,000 U of EPO, and about 100 ml of one or more modified haemoglobins. For the treatment of manifest iron deficiency anaemias the combination preparation likewise preferably contains 3,000-7,000 U of EPO and 80-100 ml of a modified haemoglobin.
As modified haemoglobins in the meaning of the invention there are suitable in principle all haemoglobins described in WO 95/24213page 20, line 15 to page 27, line 2. In particular, these are also cross-linked haemoglobins or cross-linked haemoglobin polymerizates, such as e.g. diacetylsalicylic acid (diaspirin), cross-linked haemoglobin (DCL-Hb) or other blood substitutes based on modified haemoglobins. For example, the following preparations come into consideration as modified haemoglobins: Hem Assist(copyright) (Baxter; DCL human Hb); PolyHeme(copyright) (Northfield, Upjohn, human Hb, cross-linked and polymerized); Hemopure(copyright) (Biopure, Upjohn; bovine Hb, polymerized); Optro(copyright) (Somatogen, Eli Lilly; recombinant human Hb); HemOlink(copyright) (Hemosol, Fresenius; human Hb, cross-linked and polymerized); PEG-modified bovine Hb (manufactured by Enzon; polyethylene glycol-modified Hb); polyoxyethylene-modified human Hb (manufactures Apex and Ajinimoto). The haemoglobins can also be used in accordance with the invention in the form of haemoglobin preparations which contain pharmaceutically compatible adjuvants known per se. Such preparations are described, for example, in WO 95/24213.
As suitable erythropoietin preparations in the meaning of the present invention there come into consideration those active substances which are comparable with respect to the physiological effect of human EPOs. Suitable EPO preparations are, for example, recombinant human EPO (rhEPO; see European Patent EP 0,205,564 or EP 0,411,678) or also corresponding modifications of these proteins. As modifications there come into consideration, for example, such proteins with molecular weights higher or lower than 34,000 Da (molecular weight of urinary EPO), likewise isoforms of the enzyme or proteins with different glycosylation. In particular, proteins chemically modified by PEG (polyethylene glycol) can also be used. Further, there basically also come into consideration such proteins which are derived by deletions, substitutions or additions from the amino acid sequence of the natural EPO with a length of 166 amino acids. These proteins have essentially comparable physiological properties to rhEPO. In particular, these proteins have biological properties which cause bone marrow cells to increase the production of reticulocytes and red blood corpuscles and/or to increase haemoglobin synthesis or iron uptake. In place of these proteins there can also be used low molecular substances, which are denoted as EPO mimetics, and which bind to the same biological receptor. These mimetics can preferably also be administered orally. The amount of such proteins or mimetics to be administered is determined by comparing the biological activity between EPO and these active substances.
The concentrations in accordance with the invention of EPO and haemoglobin-Fe2+permit in their combination an optimal anaemia treatment, especially the treatment of manifest anaemias. The treatment with the combination preparation is preferably effected once weekly, whereby the amount of haemoglobin of 300 ml per week should not be exceeded (e.g. 3xc3x97100 ml infusions).
In the meaning of the present invention there should be understood under the term xe2x80x9ccombination preparationxe2x80x9d not only those medicament packs in which the EPO preparation and the haemoglobin are presented in juxtaposition in a finished marketable unit pack (so-called combination pack), but also those medicament packs which either contain a suitable amount of an EPO preparation or a suitable amount of a haemoglobin in the form of the respective individual preparations, with the individual preparations with respect to the amount of contents being presented such that they can be administered in the meaning of the invention for the combined dose with the respective other preparation. In these cases there is usually enclosed with the preparations from the pharmaceutical manufacturer or the medicament importer a medicament package insert which is required by law in many countries and in which are contained directions or information concerning the combined dose of the individual preparations.
The combination preparations can preferably be present in a single administration form in which the respective amounts of the EPO preparation and the haemoglobin are present in juxtaposition in one container.
This can be e.g. an injection solution or infusion solution or its lyophilizate, which, for example, is filled into ampoules. This administration form has the advantage that the EPO is stabilized by the modified haemoglobin during the production and storage of the administration form. In the case of a lyophilizate, the EPO, after its dissolution, is activated by the modified haemoglobin. The fixed combination of the two active substances in the form of a lyophilizate has the further advantage that it can be handled simply and safely. The lyophilizate is dissolved in the ampoule by the addition of pharmaceutically usual injection media and is administered intravenously.
It is also possible to administer the EPO preparation and the modified haemoglobin in the form of separate pharmaceutical formulations (free combination) simultaneously or, however, also in succession. This free combination, which can be made available in a unit pack, has the advantage of greater flexibility. Thus, these administration forms also enable the modified haemoglobins to be administered 1-3 days prior to the EPO administration.
This free combination, which can be made available in a single unit pack (medicament pack) also has the advantage that each patient to be treated can be prescribed a particular individual amount of an EPO preparation and of a haemoglobin. Furthermore, these combination preparations offer the advantage of greater safety when performing the therapy, since in each case the optimal synchronized amount of the individual preparation is fixed. A safe therapy and simple handling by the personnel performing the treatment or in the area of self medication performed by patients is guaranteed by the combination preparation in accordance with the invention.
Where the EPO preparation is made available as a lyophilizate, the medicament packs (combination packs) contain the corresponding amount of the EPO preparation in glass ampoules or in cartridges. The haemoglobin can be present in solid form (lyophilizate) or also in liquid form in a separate container. Further, the combination pack preferably contains a reconstitution solution in order to dissolve either the EPO lyophilizate alone or also together with the haemoglobin. If the haemoglobin is present as a ready-for-use solution, the solution can be mixed together with the EPO solution when the combined administration of EPO and haemoglobin has to be effected. Basically, the haemoglobin can also be made available as a concentrate for addition to conventional infusion solutions, by which means a longer administration over several hours can be effected.
Combination preparations in the meaning of the present invention are also those unit packs which in each case make available individual administration forms of the erythropoietin preparation or of the haemoglobin as independent medicaments, with the individual preparations being provided such that they contain the requisite amounts of the individual substances for the combination in accordance with the invention of the EPO preparation and the hemoglobin. As a rule, the medicament packs contain the previously described package insert containing corresponding instructions for the combined administration with EPO or with haemoglobin in the required amount. A corresponding instruction can also be present as a pack imprint on the medicament pack (secondary packaging) or on the primary packaging (ampoule, blister strips, etc.). Thus, in the case of the EPO-containing medicament with 3,000-7,000 U of EPO it is, for example, indicated thereon that this preparation should especially be administered together with a haemoglobin preparation containing 50-100 ml of one or more modified haemoglobins. In the case of the haemoglobin preparation there is a reverse indication to the combined administration with 3,000-7,000 U of an erythropoietin preparation.
A further possibility for providing the EPO preparation comprises making available corresponding multi-dose preparations which contain the EPO preparation in higher amounts compared with individual doses. These preparations are especially suitable for use in clinics in which a large number of patients are treated daily. These multi-dose preparations contain the EPO preparation in dosages of up to 500,000 U, especially up to 100,000 or 50,000 U. The multi-dose preparations have the advantage that they permit the skilled medical personnel to withdraw any dosage of the EPO preparation, for example by withdrawing corresponding amounts by volume of the finished injection solution. This is especially advantageous in the treatment of patients with different dosage requirements of the active substance or in the treatment of children in which a lower dosage of the EPO preparation is required. From an injection solution of, for example, 100,000 U of EPO, preferably freshly prepared at the beginning of the day, there can be performed, circumstances permitting, all patient treatments required during this day without the need to prepare separate injection solutions for each of the individual patients. This can lead to a significant time saving or to an easing of the burden of work for skilled medical personnel. Preferably, the individual EPO dosages are withdrawn in the range of 3,000 U, 5,000 U and 7,000 U.
The multi-dose preparations can also be present in the form of solutions, which are filled into cartridges. These cartridges are suitable for use in so-called pens, which permit administration by patients themselves and an individual dosage withdrawal. For example, these cartridges contain the EPO preparation in an amount of 10,000 or 20,000 U, whereby different dosing intervals can be realized by appropriate adjustment of the withdrawal volume.
The production of the pharmaceutical administration forms of the invention is effected according usual processes known in galenical technology with pharmaceutically usual adjuvants. The process for the production of the pharmaceutical combination preparation in accordance with the invention and the pharmaceutical unit pack, which contains the combination of preparations in accordance with the invention, are likewise objects of the invention.
In carrying out the therapy, the diagnostic parameters ferritin and transferrin saturation have to be controlled. The ferritin value is in the normal range when it amounts to 400 xcexcg/lxc2x150%. The transferrin saturation should amount to 20-40%.
The invention will be illustrated hereinafter in more detail on the basis of working Examples.

Pharmaceutical combination preparations containing erythropoietin and modified haemoglobins