According to the present invention there is provided a method for making a lithographic printing plate including the steps of dispensing in a predetermined pattern a latex of particles of a hydrophobic polymer onto an optionally modified hydrophilic surface of a lithographic base, characterized in that the hydrophobic polymer and the optionally modified hydrophilic surface of the lithographic base have mutually reactive groups.

The present invention relates to methods for making lithographic printing plates. In particular, it relates to a method for directly making the lithographic printing plates by using hydrophobic polymer latex printing, which makes it possible to produce the lithographic plates directly from digital data output from computers, facsimiles, or the like without using any intermediate films.
Digitalization of information has made a rapid progress in recent years throughout the process from manufacturing a block copy, an upper stream process of printing, to manufacturing a printing plate, thereby putting to practical use for example, a photographic form system of characters, by which a block copy of manuscripts can be readily prepared, or a scanner which directly reads picture images. With this progress, there has arisen a demand for a direct plate-making method in which lithographic plates can be directly prepared from digital data output from computers, facsimiles, or the like without using a film for making printing plates.
As one example of the direct plate-making method, a method wherein an image or non-image portion is directly formed on a substrate by ink-jet printing is known to the art. The ink-jet printing system is a relatively rapid image output system and has a simple construction because it does not require any complex optical system. Therefore, the printing system makes an apparatus for making printing plates simple and the cost for making printing plates can be reduced since the maintenance labor is largely reduced.
As examples of the methods for preparing printing plates by using the ink-jet printing system, Japanese Kokai Publication 113456/1981 proposes the methods for preparing printing plates wherein ink-repelling materials (e.g. curable silicone) are printed on a printing plate by ink-jet printing. The printing plate obtained by this method is an intaglio printing plate in which the ink-repelling material formed on the surface of the substrate serves as a non-image part. As a result, the resolution of the printed images at shadow area or reversed lines is not so good. Moreover, a large amount of ink is needed in this method because the ink-repelling material must be deposited on the whole non-image part which occupies most of the surface of the printing plate.
U.S. Pat. No. 5,312,654 discloses a method for making lithographic printing plates comprising: forming an image on a substrate having an ink absorbing layer and a hydrophilized layer between the substrate and absorbing layer by ink-jet printing using a photopolymerizable ink composition, and exposing it to an active light in the wavelength region curing the image. The printing endurance of said printing plates is low.
EP-A- 533 168 discloses a method for avoiding ink spreading by coating the lithographic base with an ink absorbing layer which is removed after ink printing. This is an uneconomical and cumbersome method.
Research Disclosure 289118 of May 1988 discloses a method for making printing plates with the use of an ink jet wherein the ink is a hydrophobic polymer latex. However said printing plates have a poor ink acceptance and a low printing endurance.
It is an object of the invention to provide a method for making lithographic printing plates from a lithographic base having a hydrophilic surface image-wise imaged with a hydrophobic polymer latex which yields an excellent lithographic printing plate with a high printing endurance.
It is further an object of the present invention to provide a method for making lithographic printing plates without a wet development of the lithographic base in a rapid , economical and ecological way.
Further objects of the present invention will become clear from the description hereinafter.
According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of dispensing in a predetermined pattern a latex of particles of a hydrophobic polymer onto an optionally modified hydrophilic surface of a lithographic base, characterized in that said hydrophobic polymer and the optionally modified hydrophilic surface of the lithographic base have mutually reactive groups.
According to the present invention, the lithographic base may be an anodized aluminum support. A particularly preferred lithographic base is an electrochemically grained and anodized aluminum support. The anodized aluminum support may be treated to improve the hydrophilic properties of its surface. For example, the aluminum support may be silicated by treating its surface with sodium silicate solution at elevated temperature, e.g. 95xc2x0 C. Alternatively, a phosphate treatment may be applied which involves treating the aluminum oxide surface with a phosphate solution that may further contain an inorganic fluoride. Further, the aluminum oxide surface may be rinsed with a citric acid or citrate solution. This treatment may be carried out at room temperature or may be carried out at a slightly elevated temperature of about 30 to 50xc2x0 C. A further interesting treatment involves rinsing the aluminum oxide surface with a bicarbonate solution. Still further, the aluminum oxide surface may be treated with polyvinylphosphonic acid, polyvinylmethylphosphonic acid, phosphoric acid esters of polyvinyl alcohol, polyvinylsulphonic acid, polyvinyl-benzenesulphonic acid, sulphuric acid esters of polyvinyl alcohol, and acetals of polyvinyl alcohols formed by reaction with a sulphonated aliphatic aldehyde. It is further evident that one or more of these post treatments may be carried out alone or in combination. More detailed descriptions of these treatments are given in GB-A- 1 084 070, DE-A- 4 423 140, DE-A- 4 417 907, EP-A- 659 909, EP-A- 537 633, DE-A- 4 001 466, EP-A- 292 801, EP-A- 291 760 and U.S. PAT. No. 4,458,005.
According to another mode in connection with the present invention, the lithographic base with an optionally modified hydrophilic surface comprises a flexible support, such as e.g. paper or plastic film, provided with a cross-linked optionally modified hydrophilic layer. A particularly suitable cross-linked hydrophilic layer may be obtained from a hydrophilic binder cross-linked with a cross-linking agent such as a melamine-resin, formaldehyde, dialdehydes like glutaric dialdehyde glyoxal, polyisocyanate or a hydrolyzed tetra-alkylorthosilicate. The latter is particularly preferred.
As hydrophilic binder there may be used hydrophilic (co)polymers such as for example, homopolymers and copolymers of vinyl alcohol with as reactive functions hydroxyl groups, acrylamide with as reactive function an amide group, methylol acrylamide, methylol methacrylamide, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate, all with a hydroxyl function as reactive group, maleic anhydride with an anhydride as reactive group, maleic acid with a hydroxyl function as reactive group, maleic anhydride/vinylmethylether copolymers anhydride with an anhydride as reactive group. The hydrophilic binder can partially contain crosslinkable or reactive groups e.g. silanol modified polyvinylalcohol, vinylalcohol copolymer with crosslinkable acrylamides like N-(-methoxymethyl)-acrylamide, n-butoxymethyl acrylamide, n-butoxymethyl methacrylamide. The hydrophilicity of the (co)polymer or (co)polymer mixture used is preferably the same as or higher than the hydrophilicity of polyvinyl acetate hydrolyzed to an extent of at least 60 percent by weight, preferably at least 80 percent by weight.
The amount of crosslinking agent, in particular of tetraalkyl orthosilicate, is preferably at least 0.2 parts by weight per part by weight of hydrophilic binder, more preferably between 0.5 and 5 parts by weight, most preferably between 1.0 parts by weight and 3 parts by weight. The amount of cross-linking agent is not so high that no hydroxyl groups of the polyvinyl alcohol remain.
A cross-linked hydrophilic layer in a lithographic base used in accordance with the present embodiment preferably also contains substances that increase the mechanical strength and the porosity of the layer. For this purpose colloidal silica may be used. The colloidal silica employed may be in the form of any commercially available water-dispersion of colloidal silica for example having an average particle size up to 40 nm, e.g. 20 nm. In addition inert particles of larger size than the colloidal silica may be added e.g. silica prepared according to Stober as described in J. Colloid and Interface Sci., Vol. 26, 1968, pages 62 to 69 or alumina particles or particles having an average diameter of at least 100 nm which are particles of titanium dioxide or other heavy metal oxides. By incorporating these particles the surface of the cross-linked hydrophilic layer is given a uniform rough texture consisting of microscopic hills and valleys, which serve as storage places for water in background areas.
In a particular embodiment, the lithographic base comprises a hydrophilic binder which comprises reactive groups selected from the group consisting of epoxides, alkoxysilanes and reactive acrylamides which can react with hydroxyl, amino or amido functions of the hydrophobic polymer.
The thickness of a cross-linked hydrophilic layer in a lithographic base in accordance with this embodiment may vary in the range of 0.2 to 25 xcexcm and is preferably 1 to 10 xcexcm.
Particular examples of suitable cross-linked hydrophilic layers for use in accordance with the present invention are disclosed in EP-A- 601 240, GB-P- 1 419 512, FR-P- 2 300 354, U.S. Pat. Nos. 3,971,660, 4,284,705 and EP-A- 514 490.
As flexible support of a lithographic base in connection with the present embodiment it is particularly preferred to use a plastic film e.g. substrated polyethylene terephthalate film, substrated polyethylene naphthalate film, cellulose acetate film, polystyrene film, polycarbonate film etc . . . The plastic film support may be opaque or transparent. Also suitable as flexible support is glass with a thickness less than 1.2 mm and a failure stress (under tensile stress) equal or higher than 5xc3x97107 Pa.
It is particularly preferred to use a polyester film support to which an adhesion improving layer has been provided. Particularly suitable adhesion improving layers for use in accordance with the present invention comprise a hydrophilic binder and colloidal silica as disclosed in EP-A- 619 524, EP-A- 620 502 and EP-A- 619 525. Preferably, the amount of silica in the adhesion improving layer is between 200 mg per m2 and 750 mg per m2. Further, the ratio of silica to hydrophilic binder is preferably more than 1 and the surface area of the colloidal silica is preferably at least 300 m2 per gram, more preferably at least 500 m2 per gram.
A latex is defined as a stable colloidal dispersion of a polymeric substance in an aqueous medium. The polymer particles are usually approximately spherical and of typical colloidal dimensions: particle diameters range from about 20 to 1000 nm. The dispersion medium is usually a dilute aqueous solution containing substances such as electrolytes, surfactants, hydrophilic polymers and initiator residues. The polymer latices are classified in various way. By origin, they are classified as natural latices, produced by metabolic processes occuring in the cells of certain plant species; synthetic latices, produced by emulsion polymerization of monomers; and artificial latices, produced by dispersing a polymer in a dispersing medium or by solvent exchange.
Preferred latices in connection with the invention are synthetic and artificial latices. These artificial latices are rather referred to as polymer dispersions. These polymers or oligomeric species could be dispersed in water either before their polymerization and/or crosslinking or afterwards. The colloidal stability of the dispersion can be improved by the addition of dispersion agents (surface-active compounds) or by ionic groups incorporated via the monomeric species or via modification. The dispersions of the polymers (or oligomers) can contain crosslinking agents, polymerization catalysts, or incorporated species which can give self-crosslinking of the polymer, to obtain sufficient mechanical strength.
A hydrophobic polymer according to the invention is a polymer which comprises at least one monomer with a reactive group. Examples of suitable reactive groups are alkoxysilane groups, oxazoline groups and activated carboxylic acids, e.g. carbodiimide derivatives and preferably epoxide groups and trialkoxysilane groups. Said reactive groups are contained in the side chain of the hydrophobic polymer. Alkoxysilane containing monomers can contain the following polymerizable groups: acrylate, methacrylate, acrylamide, methacrylamide, vinyl ether, styrene-derivatives.
The reactive group in the hydrophobic polymer can be introduced in the hydrophobic polymer by copolymerization of monomers comprising said reactive groups or can be introduced by chemical modification of said hydrophobic polymer.
Preferably said hydrophobic polymer is a copolymer containing at least a comonomer without a reactive group. Said hydrophobic polymer comprises a comonomer with a reactive group in a range of 1 to 50% by weight, more preferably in a range of 3 to 30 % by weight of the polymer.
Said hydrophobic copolymers are preferably polymers dispersed in water, prepared by chain copolymerization of monomers like styrene, styrene derivatives, acrylates, methacrylates, acrylamides, methacrylamides, or olefines, or prepared by step polymerization and forming polymers like polyurethanes, polyethers, polyamides, polyamic acids and polyether imides.
Hydrophobic copolymers for use in synthetic latices according to the present invention are, for example, polystyrene and styrenic copolymers such as styrene/butadiene/acrylic acid copolymers, polyacrylates such as polymethyl methacrylate and polybutyl acrylate, copolymers of butyl acrylate and methyl methacrylate, copolymers of butyl acrylate and styrene, copolymers of butadiene and methyl methacrylate.
Hydrophobic polymers for use in artificial latices according to the present invention are, for example polyurethanes such as the reaction product of a diisocyanate with a hydroxyl terminated polymer or oligomer (such as polyglycol or polyester) or reaction products of diisocyanates with amine-functional dialcohols (such as N-methyldiethanolamine, which can be quaternized e.g. using dimethylsulphate, methyliodide or 1,4-dibromobutane). These polymerizations are carried out in an organic solvent such as acetone, tetrahydrofurane, The polyurethanes soluble in polar organic solvents are mixed with water, and the organic solvent is eliminated from the aqueous-organic solutions to produce stable polyurethane latices (e.g. as described by D. Dieterich, Angew. Macromol. Chem., 76, 79 (1979), J. Dieterich et al., J. Oil Col. Chem. Assoc., 53, 636, (1970), V. S. Reddy, J. Dispers. Sci.Technol., 14, 417, (1993)). Stabilization of the polyurethane dispersions can also be achieved via anionic groups such as carboxylate, sulphonate, phosphonate. Addition of a dispersion agent (surface active compound) can give sufficient stabilization to the polyurethane latex. Diisocyanates which could be used to produce the polyurethanes could be aliphatic or aromatic, for example hexametylene 1,6-diisocyanate, isophorone diisocyanate, 1,6-diisocyanatotrimethylcyclohexane, diphenylmethane 4,4xe2x80x2-diisocyanate, naphthalene 1,5-diisocyanate.
In order to facilitate the evaluation of the obtained lithographic plate colored hydrophobic polymer synthetic or artificial latices can be used. For example, carbon black or dyes or pigments can be mixed with one of the above mentioned copolymers. Also polymer particles containing color structures in the repeating units, in particular colored polymer particles which have obtained their color by means of a chemical reaction based on oxidative coupling of a color coupling group in the polymer structure of the particles with an aromatic primary amino compound, as described in Japanese Kokai 59/30873 can be used as colored hydrophobic polymer latex.
The hydrophobic polymer synthetic or artificial latex particles have preferably a particle size between 0.01 and 1 xcexcm, more preferably between 0.01 xcexcm and 0.25 xcexcm.
The latex can contain from 1 to 70% by weight of hydrophobic polymer, more preferably from 2 to 40% by weight of hydrophobic polymer, most preferably from 5 to 30% by weight of hydrophobic polymer.
The latex can be dispensed onto the lithographic base having a hydrophilic surface preferably by an ink jet printer.
A volatilization preventive agent is added to the latex according to the present invention, if necessary, to suppress evaporation of the liquid in the ink-jet nozzle and to prevent clogging due to precipitation of the dissolved or dispersed components.
A surfactant is preferably added to the the latex used according to the present invention to adjust the size of droplets of the latex dispersed by the ink jet nozzle, to adjust the surface tension of the latex so that images can be formed in high resolution. Said surfactant can be an anionic, a cationic, a non-ionic or an amphoteric compound.
Other components can be further added, if necessary, to the latex used according to the present invention. For example, heat polymerization inhibitors, disinfectants, anticontamination agents and anti-fungal agents can be also added. Use of buffers and solubilizers is effective to improve the solubility or dispersibility of the polymer. Addition of defoaming agents and foam suppressing agents are also possible to suppress foaming of the latex in the ink-jet nozzle.
The image forming requires the following steps. On demand, microdots of the hydrophobic polymer latex are sprayed onto the lithographic base in a predetermined pattern as the plate passes through the printer or by a printhead shuttling over the plate. According to one embodiment of the invention, the microdots have a diameter of about 20 xcexcm. In a following step heating may be required for the lithographic base sprayed with hydrophobic polymer latex. This can be done by irradiation, by convection or by contact with a hot surface e.g. in an oven, by flash exposure, by IR-heaters or by laser irradiation.
The image forming can also be carried out with the lithographic e already on the printing cylinder. In that case the heating of polymer can be effected by using a heated printing cylinder.
The printing plate of the present invention can also be used in printing process as a seamless sleeve printing plate. This indrical printing plate has such a diameter that it can be slided the print cylinder. More details on sleeves are given in xe2x80x9cGafisch Nieuwsxe2x80x9d ed. Keesing, 15, 1995, page 4 to 6.
The following examples illustrate the present invention without limiting it thereto. All parts and percentages are by weight unless otherwise specified.

Method for making positive working printing plates from a latex


A portable paging system for responsive signaling between a first person and a second person. The portable paging system includes a housing. The housing has a top side, a bottom side and peripheral wall integrally coupled to the bottom and top sides and extending therebetween such that the housing is generally hollow. A microprocessor is adapted to receive a transmitted signal and illuminate a light. The microprocessor is securely mounted in the housing. A light is securely mounted to the top side of the housing. The light is electrically coupled to the microprocessor. A receiver receiving a transmitted signal is positioned in the housing and operationally coupled to the microprocessor. A transmitting device selectively transmits a signal to the receiver over a distance of less than one mile.

1. Field of the Invention
The present invention relates to paging systems and more particularly pertains to a new portable paging system for responsive signaling between a first person and a second person.
2. Description of the Prior Art
The use of paging systems is known in the prior art. More specifically, paging systems heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art includes U.S. Pat. No. 5,680,119; U.S. Pat. No. 5,021,780; U.S. Pat. No. 4,797,671; U.S. Pat. No. 5,710,548; U.S. Pat. No. 5,728,556; U.S. Des. Pat. No. 409,577; U.S. Pat. No. 5,808,560; and U.S. Pat. No. 5,668,543.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose a new portable paging system. The inventive device includes a housing. The housing has a top side, a bottom side and peripheral wall integrally coupled to the bottom and top sides and extending therebetween such that the housing is generally hollow. A microprocessor is adapted to receive a transmitted signal and illuminate a light. The microprocessor is securely mounted in the housing. A light is securely mounted to the top side of the housing. The light is electrically coupled to the microprocessor. A receiver receiving a transmitted signal is positioned in the housing and operationally coupled to the microprocessor. A transmitting device selectively transmits a signal to the receiver over a distance of less than one mile.
In these respects, the portable paging system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of responsive signaling between a first person and a second person.


A method of fabricating a display panel comprises the steps of: forming a controlling elements array substrate and a flexible color filter, respectively; forming a displaying medium on the controlling elements array substrate; and assembling the flexible color filter to the controlling elements array substrate for disposing it on the displaying medium layer. A method of fabricating a flexible color filter comprises the steps of: forming a flexible substrate on a rigidly substrate; forming a color filter film comprising a plurality of color filter patterns; and separating the flexible substrate from the rigidly substrate. Since the color filter film are formed before separating the flexible substrate from the rigid substrate, the flexible color filter may have good resolution and process yield.

1. Field of the Invention
The invention relates to a method of fabricating display panel, and more particularly, to a method of fabricating display panel with flexible color filter.
2. Description of the Related Art
With progress of the flat display technique, more and more electrical products, especially portable electrical products such as mobile phones, e-books, digital cameras and personal digital assistants etc., are equipped with flat display apparatuses. The development trend of the portable electrical product is to achieve light weight and thin thickness, so the flat display apparatus for the portable electrical product should have these features.
It is well known that the flexible panel display not only has features of light weight and thin thickness, but also has features of flexibility and is not easy to be broken. Therefore, the development of the flexible panel display has become increasingly important. During the fabricating process of conventional flexible panel display, a controlling elements array and a color filter film are printed on plastic substrates respectively by roll-to-roll printing process first. Then, the substrates are assembled to each other.
However, the yield and the capacity of the roll-to-roll printing process are limited since the steadiness thereof is not good enough. Furthermore, the resolution of the controlling elements or the color filter film formed by the roll-to-roll printing process only achieve to about 30 micrometer. It is not corresponding to the tendency toward request the resolution of the nowadays display panel to 1 micrometer.
Besides, since the controlling elements array or the color filter film are printed on the plastic substrates by ink jet printing during the conventional roll-to-roll printing process, the accuracy of process is more difficult to control than the accuracy of the lithographic and etching process. Moreover, the controlling elements array or the color filter film may be not even because the quantity of ink jetted by the clogged jet head is not uniform.

Methods of fabricating display panel and flexible color filter thereof


There is provided an HSV complex which comprises an avirulent HSV and a targeting agent which allows the HSV particle to infect and lyse a specific targeted cell. The inventors have found a way in which avirulent HSV can be targeted to disease cells, e.g. cancer cells, by incorporating an antibody binding domain into one or more viral glycoproteins.

HSV is an enveloped, icosahedral, double-stranded DNA virus that infects mammals, including humans. Wild-type HSV infects and replicates in both terminally differentiated cells and dividing cells. Wild type HSV is neurovirulent, entering the peripheral nervous system where active viral replication is suppressed and the virus remains latent in neurones. HSV can reactivate from the latent state to produce infectious lesions. The HSV neurovirulence gene ICP34.5 is believed to condition post-mitotic cells (particularly neurones) for viral replication. (Thompson et al. Virology 172, 435-450 (1989); MacLean et al., J. Gen Virol. 72, 631-639 (1991); Harland and Brown, J. Gen Virol. 66, 1305-1321 (1985); and Taha et al., J. Gen Virol. 70, 705-716 (1989)). ICP34.5 deletion mutants cannot replicate in terminally differentiated cells but can lytically infect dividing cells (Brown, S. M et al. 75, 2367-2377 (1994)). The HSV-1 mutant strain 1716 is an ICP34.5 deletion mutant (EP-B-O 571,410) of HSV type I strain 17, that has reduced virulence and greatly reduced lethality in mice, but it replicates as efficiently as wild type virus in actively dividing tissue culture cells (Maclean, A. R. et al. J. Gen Virol. 72 631-639 (1991), Brown, S. M. et al, J. Gen Viral. 75 2367-2377 (1994)). The ability of ICP34.5 deletion mutants to specifically target and lyse dividing cells and not post mitotic cells makes them an attractive therapeutic agent for the treatment of cancer. HSV infection of rapidly dividing cancer cells leads to death of the cells by lysis. The 1716 mutant kills tumour cell lines in tissue culture and, in a range of in vivo cancer models, the virus was shown to induce tumour regression and prolong survival (Kesari, S., Randazzo, B. P. and Valyi-Nagy, T. Lab Invest. 73 636-648 (1995), MacKie E. A. et al. Br J. Cancer 74 745-752 (1996), Randazzo, B. P. et al. J. Invest Dermatol. 108 933-937 (1997)). In clinical trials, direct injection of 1716 was effective in treating patients with recurrent glioma (Rampling, R. et al. Gene Therapy 7 (10) 859-866 (2000)) and metastatic melanoma (MacKie, R. M., Stewart, B. and Brown, S. M. The Lancet 357 525-526 (2001)).
Significantly, in both of these trials there was no evidence for spread of 1716 to surrounding normal tissue. A second HSV-1 ICP34.5 deletion mutant, G207, which additionally lacks the UL39 gene that encodes the large subunit of the viral ribonucleotide reductase, has also been shown to be safe and effective in patients with malignant glioma (Markert, J. M. et al. Gene Therapy 7 (10), 867-874 (2000)).
Although strains such as 1716 and G207 that have impaired neurovirulence and that selectively infect dividing cells have strong therapeutic potential for the treatment of human malignancies, some limitations of their use are anticipated by the inventors. 1716 is able to infect and kill a variety of tumour cells in tissue culture, but its permissive range in vivo may be more restricted. For example, 1716 infection of B or T cell lymphomas has not been reported. Additionally, the virus may infect tumour cells less efficiently in vivo than in cell culture. The inventors have appreciated that it is desirable to overcome certain cell-type restrictions and increase the efficiency of infection of tumour cells so that modified HSV can be more widely, effectively and safely applied as an in vivo therapy.
Broadly, the present invention provides a means of altering or modifying the tropism of HSV, so that a particular range of cell types can be targeted.
At its most general, the present invention provides an HSV complex comprising a modified HSV and a targeting agent capable of targeting said modified HSV to a specific cell type, preferably a proliferating cell e.g. a cancer cell. The invention further provides a method of producing the HSV complex and its use of the complex in the treatment of diseases such as cancer.
Thus, in a first aspect, the present invention provides an HSV complex comprising an HSV linked to a targeting agent, capable of targeting a specific cell type, where the genome of said HSV is modified in the terminal portion of RL within Bam HI s (0-0.02 and 0.81-0.83 mu).
The targeting agent is conveniently an antibody or component of an antibody, e.g. an antibody binding domain. The antibody is preferably capable of specifically binding to a cell surface protein present of the cell type targeted. This is discussed below. The targeting agent is preferably linked to the modified virus via a viral envelope protein so that it is displayed on the surface of the virus. A convenient way of achieving this is to form a fusion protein comprising the targeting agent and a viral envelope protein such as a glycoprotein. Alternatively, the targeting agent may be linked to the viral particle by chemical means, e.g. co-valently, or by a binding agent, e.g. avidin/strepavidin and biotin.
In a preferred embodiment, nucleic acid encoding the targeting agent is incorporated into the viral genome so that it is expressed as a fusion protein with a viral envelope protein e.g. a glycoprotein, and as a result displayed on the surface of the particle.
Thus, the invention provides an HSV which is capable of targeting a specific cell type, said HSV lacking an expressible γ34.5 gene so as to lack neurovirulence and wherein the HSV expresses a targeting agent.
As an antibody binding domain forms a preferred embodiment of the invention, the following description will concentrate on the use of antibodies. However, it will be apparent to the skilled person that other targeting agents may be used, e.g. members of a specific binding pair such as a receptor and its ligand.
The antibody or antibody component incorporated into the viral envelope influences the selectivity of the virus by enhancing the efficiency of viral infection of a certain cell type or cell types. The HSV infection process is initiated through contact between glycoproteins of the viral envelope and glycoproteins of the target cell membrane. In the present invention, antibodies with specific affinity for membrane proteins of the chosen cell type are incorporated into the HSV viral envelope, increasing the affinity of the HSV for the surface of the chosen target cell through the additional interaction between the antibody and the cell surface protein. The binding of the antibody binding domain to its target antigen on the cell surface will bring both virion and cellular membranes into closer proximity and allow the viral envelope glycoproteins to initiate fusion of the membranes, leading to penetration of the cell.
The HSV-1 virion envelope contains at least 10 integral membrane glycoproteins, several of which mediate entry into mammalian cells. The initial interactions between the virus and the cell are between viral glycoproteins gB and/or gC and cell surface heparin sulphate proteoglycans, but this interaction is insufficient for viral penetration. Fusion of the viral and cellular membranes requires gD, gB and a gH/gL complex, and these proteins are presumed to act in concert. Specific receptor-mediated entry of HSV-1 involves interaction of gD with HVEM/HveA (herpesvirus entry mediator A), a lymphotoxin receptor and member of the TNF receptor family. Expression of HveA in CHO cells that are normally refractory to viral penetration rendered them permissive. Several other receptors have been identified using non-permissive CHO cells including the poliovirus receptor related proteins 1 and 2, now renamed HvecC and HvecB respectively. For this work, the inventors have been able to render a cell line normally resistant to infection permissive for HSV-1 entry.
The present invention uses an HSV that has an impaired ability to infect, replicate in or lyse terminally differentiated, non-dividing cells. In this form the virus is particularly suited for use as a therapeutic agent to treat diseases associated with proliferating cells such as cancer and non-cancer diseases such as Crohn's disease. The inventors believe the modified virus in accordance with the present invention will be particularly useful in targeting proliferating T-cells in cancer or non-cancer situations.
In a preferred embodiment, the HSV has been modified so that the gene encoding ICP 34.5 (gene γ34.5) is incapable of expressing a functional gene product.
The modified virus preferably contains a modification in respect of the wild type virus within the Bam HI s region of the internal repeat RL (0.81-0.83 mu) and within the counterpart region of the terminal RL (0-0.02 mu) such that the modified virus (variant) lacks neurovirulence.
The modification of the virus genome may be achieved by deletion of one or more nucleotides, insertion of additional nucleotides or any other alteration of the nucleotide sequence such as rearrangement, or substitution. Preferably, the modification of the HSV genome is achieved by deletion of one or more nucleotides.
The HSV may be a spontaneously isolated deletion variant of the wild type or it may be a wild type strain into which the desired modification has been introduced. Such modifications in the HSV may be made by genetic manipulation, for example by site-directed mutagenesis, or by excision of a portion of the genome with or without replacement with a pre-prepared DNA cassette incorporating the required modification.
Preferably, the HSV is HSV type I (HSV-I) even more preferably HSV-1 strain 17. In one embodiment, the HSV-1 strain will have a deletion of at least 100 nucleotides in the Bam HI s′ region between Alu I site at 125074 nb and 125972 nb and within its counterpart sequence in TRL.
More preferably 0.5 to 3 kb of the Bam HI s′ region and its counterpart in TRL is deleted. Still more preferably about 0.7-2.5 kb is deleted.
Suitable modified HSV include HSV-1 mutant 1716 or G207. The production of HSV1716 is described in EP 571,410-B which is incorporated herein by reference.
In addition to the above, the inventors have appreciated that, in order to treat a diverse range of tumours, the HSV complex in accordance with the invention will ideally have to be administered into the circulation of a patient. However, not only does the virus have to find the tumour cells (it can bind and be adsorbed by many different cell types) but it also has to contend with pre-existing immunological defenses (e.g. neutralising antibodies) designed to eliminate the virus. Pre-existing immunological defenses will be reasonably common as most people have had previous exposure to HSV-1. Given this, the present inventors have appreciated that there is a need to develop a "stealth" virus that avoids immunological detection and can specifically target tumour cells. Accordingly, the inventors have produced a stealth virus by eliminating the normal viral glycoproteins that mediate cell adsorption and replacing them with antibody-directed entry mediating glycoproteins incorporated into the virion structure. The principal viral glycoproteins involved in cell entry also provide the main neutralising epitopes and their removal will minimise immunological activity against such a virus. Thus, tumour antigen-directed HSV e.g. HSV1716 introduced into the circulation can target many tumour types including disseminated cancers that are either inaccessible or too numerous for direct injection or are too small to be detected.
Thus, the HSV complex as described above, e.g. HSV1716, that displays a tumour specific targeting antibody in accordance with the first aspect of the present invention, may be modified such that the genes encoding viral glycoproteins essential for normal cell entry (e.g. principally gD but also gC and/or gB, see below) are deleted or inactivated, thereby rendering the resulting virus dependent on tumour antigen/antibody interactions as the main route for cell infection. Deletion of these glycoproteins from the virus particle also removes the principal neutralising epitopes and therefore greatly reduces immunological defenses when administered systemically.
Therefore, the HSV complex according to the first aspect of the present invention may be further modified so that one or more viral glycoproteins, e.g. gD, gC and/or gB, are inactivated or deleted such that they are unable to mediate entry of the viral particle into cells. It is preferable that the one or more glycoproteins are modified at the genome level such that they cannot be expressed or cannot be expressed in a functional form. It is most preferable that the HSV genome is modified so that the one or more glycoproteins cannot be expressed at all as this will provide the HSV variant with the additional advantage that it can escape any pre-existing immunological defenses in vivo.
As mentioned above, the various glycoproteins may be modified or deleted from the viral particle, preferably at a nucleic acid level. The modification may include the incorporation of nucleic acid encoding the targeting agent so that the targeting agent is expressed on the surface of the particle. Thus, the HSV genome may be modified, in addition to the γ34.5 gene, such that one or more of the glycoproteins (e.g. gD, gC and/or gB) express the targeting agent, e.g. the antibody binding domain.
Preferably, the antibody or antibody component is specific for tumour surface antigen, i.e. antigen found on the surface of a tumour cell and associated with that cell, being either unique to tumour cells or being more abundant on tumour cells than on most if not all nontumour cells. Many novel or atypical forms of normal proteins are expressed by tumour cells, and antibodies directed against these provide tumour targeting strategies. For example, carcinoembryoinic antigen (CEA) is an important marker on many tumour cells and engineered antibodies directed against CEA have undergone clinical trials (Mayer, A. et al., J. Immunol. Methods 231 261-273 (1999)). Engineered antibodies directed against the Her2/neu growth factor (Trastuzamab) and against CD20 (rituximab) have been licensed for the treatment of breast cancer and Non-Hodgkin's lymphoma respectively Holliger, P. and Hoogenboom, H. (1998), Nature Biotechnology 16, 1015. CD55 (decay accelerating factor) is over-expressed by tumour cells to block complement activation and antibodies directed against CD55 may have therapeutic potential (Li, L. et al. B. J. Cancer 84 (1) 80-86 (2001)). Incorporation of an antibody binding domain that specifically targets tumour antigens such as CRA, Her2, CD20 and CD55 into the envelope of HSV will have the potential to alter its cellular tropism thus allowing infection of non-permissive tumour cells and possibly improving its ability to infect other tumour cells. For example, 1716 virions that display an antibody binding domain specific for CD20 may be able to infect and kill B-cell lymphomas.
Further, HSV, e.g. HSV1716 virions that display tumour targeting antibodies and from which the normal HSV-1 entry glycoproteins are deleted will only infect the targeted tumour cells.
The antibody binding domain may have specific affinity for a cell surface protein found on the cell type from which the tumour originated, e.g. in the case of a glioma, the antibody or antibody component incorporated into the HSV viral envelope would be specific for an antigen commonly associated with glial cells. The specificity of the avirulent HSV strain for infecting dividing cells would therefore be further modified so that glial cells were preferentially infected by the virus more than other types of dividing cells. By targeting dividing glial cells, the HSV should infect and lyse glioma cells more efficiently than any other cells. The use of antibodies or antibody components against particular cell types can also be used to extend the tropism of HSV to cell types that are not otherwise efficiently infected by HSV, e.g. the use of antibodies or antibody components specific for antigen found on B cells would be expected to extend the tropism of HSV to B cells. Antibodies or antibody components of different specificities may be included together in one HSV viral envelope. The combination of these specificities would be expected to give greater specificity of targeting to the desired cell type.
The antibody binding domain would preferably be fused to an integral membrane protein in the viral envelope, preferably an HSV glycoprotein. The preferred HSV-1 and HSV-2 glycoproteins are gB, gC and gD.
In a preferred embodiment, the antibody binding domain is in the form of a single chain variable fragment (scFv).
In a second aspect, the present invention comprises a method of making a modified HSV complex according to the first aspect of the invention comprising the step of infecting a cell line that constitutively expresses said fusion protein with an HSV, preferably a modified HSV, more preferably modified HSV-1.
In a third aspect, the present invention comprises a method of making a modified HSV complex according to the first aspect of the invention comprising the step of incorporating DNA encoding said fusion protein into the viral genome of the modified HSV.
In a fourth aspect, the present invention comprises the use of a modified HSV complex according to the first aspect of the invention in a method of medical treatment.
Preferably, the method comprises administering the HSV modified complex to a patient suffering from a disease associated with proliferation of cells, e.g. cancer, wherein the HSV complex selectively lyses dividing cells.
There is also provided a pharmaceutical composition which comprises the modified HSV in accordance with the present invention and a pharmaceutically acceptable carrier.
Pharmaceutical compositions comprising the modified HSV may be administered intravenously or directly injected into a tumour or infected site.

This patent is subject to a terminal disclaimer.


Aerosol formulations substantially free of chlorofluorocarbons, for oral and/or nasal administration, are described. The formulations comprise 1,1,1,2-tetrafluoroethane, a medicament, optionally an excipient and optionally a surfactant. Methods of treatment using the formulations also are described.

The present invention is directed at aerosol formulations which are substantially free of chlorofluorocarbons (CFC""s). More specifically, the present invention is directed at formulations substantially free of CFC""s and having particular utility in medicinal applications, especially in metered dose pressurized inhalators (MDI""s).
Metered dose inhalators have proven to be an effective method for delivering medicaments orally and nasally. They have been used extensively for delivering bronchodilating and steroidal compounds to asthmatics and may also be useful for delivering other compounds such as pentamidine and non-bronchodilator anti-inflammatory drugs. The rapid onset of activity of compounds administered in this manner and the absence of any significant side effects have resulted in a large number of compounds being formulated for administration via this route. Typically, the drug Is delivered to the patient by a propellant system generally comprising one or more propellants which have the appropriate vapor pressure and which are suitable for oral or nasal administration. The more preferred propellant systems typically comprise propellant 11, propellant 12, propellant 114 or mixtures thereof. Often the vapor pressure of the propellant systems is adjusted by admixing a liquid excipient with the propellant.
However, propellants 11, 12 and 114 belong to a class of compounds known as chlorofluorocarbons, which have been linked to the depletion of ozone in the atmosphere. It has been postulated that ozone blocks certain harmful UV rays and that a decrease in the atmospheric ozone content will result in an increase in the incidence of skin cancer. In the 1970""s certain steps were taken to reduce the CFC emissions from aerosols. Other propellants, such as hydrocarbons, were used, or the product was delivered in a different manner. Because CFC usage in medicinal applications is relatively low i.e. less than 1% of total CFC emissions, and because of the health benefits associated with metered dose inhalators, steps were not taken at that time to restrict the use of CFC propellants in metered dose inhalators.
However, continuing and more sophisticated ozone measurements have indicated that the earlier restrictions in CFC usage were insufficient and that additional, significant steps should be taken to drastically reduce CFC emissions. Recently, recommendations have been made that CFC production be virtually discontinued by the end of this century. As a result, it may not be possible to continue to use CFC propellants in the intermediate and long term. While some efforts have been made to use non-pressurized metered dose inhalators, many of these devices have not been completely successful. Many do not deliver uniform doses, are mechanically complex, do not provide the 100-200 doses per unit of current aerosol containers, are difficult for individuals to utilize, are bulky and/or cumbersome for the patients to use, particularly when they have an acute need for the medication.
As a result, there is a need for aerosol formulations substantially free of CFC""s. Non-CFC propellants must meet several criteria for pressurized metered dose inhalators. They must be non-toxic, stable and non-reactive with the medicament and the other major components in the valve/actuator. One propellant which has been found to be suitable is CF3xe2x80x94CH2F, also known as Freon 134a, HFA 134a, HFC 134a or 1,1,1,2 tetrafluoroethane. However, the physical properties, i.e. vapor pressure, polarity, solubility, density and viscosity of HFC 134a differ from those of commonly used propellants. Propellant HFC 134a has a vapor pressure of 5.84xc3x97105 newton/meter2 absolute (84.7 psia), which is too high for use in metered dose inhalators. In addition, commonly used surfactants may be insoluble in HFC 134a. Moreover, where the medicament is to be delivered as a solution, the medicament may not be readily soluble in this propellant. The density and polarity difference between HFC 134a and the previously used CFC propellant may result in a different delivery of the medicament when HFC 134a replaces a CFC propellant. The medicament may cream, settle or agglomerate in the non-CFC propellant even though this did not occur in the CFC propellant.
The use of HFA 134a previously has been disclosed for use in medicinal inhalators. European Patent Publication No. 0 372 777 is directed at medicinal aerosol formulations incorporating Freon 134a and an adjuvant having a higher polarity than the propellant. This publication lists several possible adjuvants and surfactants for use in combination with the propellant and the medicament.
International patent application No. WO 91/04011 discloses the combination of 1,1,1,2 tetrafluoroethane and a powdered medicament pre-coated with a non-perfluorinated surfactant prior to dispersing the powdered medicament in the propellant. Pages 6-7 of the publication list suitable surfactants for use with the propellant. A perfluorinated adjuvant optionally could be added. However, the pre-coating of the medicament may not be advantageous, since it adds an additional, complex step to the manufacturing process.
Research Disclosure No. 30161, May 1989 discloses that non-CFC propellants such as fluorohydrocarbons may be used in pressurized medicaments delivered directly to the lungs e.g. bronchodilators.
U.S. Pat. No. 4,174,295 discloses the combination of HFC 134a with various chlorofluorocarbons and optionally a saturated hydrocarbon.
U.S. Pat. No. 2,885,427 discloses the use of HFC-134a as an aerosol propellant.
U.S. Pat. No. 3,261,748 discloses the use of HFC-134a for anesthesia.
U.S. Pat. Nos. 4,129,603, 4,311,863, 4.851,595 and European Publication No. 379,793 also disclose the use of HFC-134a as an aerosol propellant.
However, the specific combinations noted above may not provide the desired solubility, stability, low toxicity, exact dosage, correct particle size (if suspension) and/or compatibility with commonly used valves assemblies of metered dose inhalers.
The present invention is directed at non-toxic formulations substantially free of CFC""s, having improved stability and compatibility with the medicament and valve components and which are relatively easily manufactured.
The present invention also is directed at formulations which may be utilized in present aerosol filling equipment with only relatively minor modifications and without pre-coating the medicament.
The invention includes an aerosol formulation comprising:
A. an effective amount of medicament; and
B. 1,1,1,2 tetrafluoroethane.
The formulation optionally may further comprise an excipient preferably selected from the group consisting of:
propylene glycol diesters of medium chain fatty acids;
triglyceride esters of medium chain fatty acids;
perfluorodimethylcyclobutane;
perfluorocyclobutane;
polyethylene glycol;
menthol;
lauroglycol;
diethylene glycol monoethylether;
polyglycolized glycerides of medium chain fatty acids;
alcohols;
eucalyptus oil;
short chain fatty acids;
and combinations thereof.
The formulation optionally may further comprise a surfactant. The surfactant preferably is selected from the group consisting of:
oleic acid;
sorbitan trioleate;
cetyl pyridinium chloride;
soya lecithin;
polyoxyethylene(20) sorbitan monolaurate;
polyoxyethylene(20) sorbitan monostearate;
polyoxyethylene(20) sorbitan monooleate;
polyoxypropylene-polyoxyethylene block copolymers;
polyoxyethylene (10) stearyl ether;
polyoxyethylene (2) oleyl ether;
polyoxypropylene-polyoxyethylene-ethylenediamine block copolymers;
castor oil ethoxylate; and combinations thereof.
The preferred liquid excipients are diethylene glycol monethyether, propylene glycol diesters of medium chain fatty acids, perfluorodimethylcyclobutane and polyethylene glycol.
The preferred surfactants are oleic acid; sorbitan trioleate, cetylpyridinium chloride; polyoxyethylene (20) sorbitan monolaurate; polyoxypropylene-polyoxyethylene block copolymers; soya lecthin; and polyoxypropylene-polyoxyethylene-ethylenediamine block copolymers; with oleic acid being particularly preferred.
The invention is of particular utility where the medicament is albuterol, mometasone furoate or beclomethasone dipropionate, and salts and clathrates thereof.
A formulation range comprises:
The present invention also is directed at a method of treating asthma in mammals comprising administering to a mammal in need of such treatment an effective amount of aerosol formulation comprising:
A. a medicament selected from the group comprising albuterol, mometasone furoate, beclomethasone dipropionate, and salts and clathrates thereof;
B. 1,1,1,2 tetrafluoroethane; and
C. optionally an excipient, preferably selected from the group consisting of:
propylene glycol diesters of medium chain fatty acids;
triglyceride esters of medium chain fatty acids;
perfluorodimethylcyclobutane;
perfluorocyclobutane;
polyethylene glycol;
menthol;
lauroglycol;
diethylene glycol monoethylether;
polyglycolized glycerides of medium chain fatty acids;
alcohols;
short chain fatty acids;
eucalyptus oil; and combinations thereof.
A surfactant optionally is present. The surfactant preferably is selected from the group consisting of:
oleic acid;
sorbitan trioleate;
cetyl pyridinium chloride;
soya lecithin;
polyoxyethylene (20) sorbitan monolaurate;
polyoxyethylene (20) sorbitan monostearate;
polyoxypropylene-polyoxyethylene block copolymers;
polyoxyethylene (10) stearyl ether
polyoxyethylene (2) oleyl ether
polyoxyethylene-polyoxypropylene-ethylene diamine block copolymers
castor oil ethoxylate; and combinations thereof.
The formulations of the present invention all utilize propellant 134a in combination with the medicament, optionally a liquid excipient and optionally a surfactant. The excipient facilitates the compatibility of the medicament with the propellant and also lowers the discharge pressure to an acceptable range i.e. about 2.76-5.52xc3x97105 newton/meter2 absolute (40 to 80 psia), preferably 3.45-4.83xc3x97105 newton/meter2 absolute (50 to 70 psia). The excipient chosen must be non-reactive with the medicament, relatively non-toxic, and should have a vapor pressure below about 3.45xc3x97105 newton/meter2 absolute (50 psia). As used hereinafter the term xe2x80x9cmedium chain fatty acidsxe2x80x9d refers to chains of alkyl groups terminating in a xe2x80x94COOH group and having 6-12 carbon atoms, preferably 8-10 carbon atoms. The term xe2x80x9cshort chain fatty acidsxe2x80x9d refers to chains of alkyl groups terminating in a xe2x80x94COOH group group and having 4-8 carbon atoms. The term xe2x80x9calcoholxe2x80x9d includes C1-C3 alcohols, such as methanol, ethanol and isopropanol. Among the preferred excipients are:
propylene glycol diesters of medium chain fatty acids available under the tradename Miglyol 840 (from Hxc3xcls America, Inc. Piscataway, N.J.);
triglyceride esters of medium chain fatty acids available under the tradename Miglyol 812 (from Hxc3xcls);
perfluorodimethylcyclobutane available under the tradename Vertrel 245 (from E.I DuPont de Nemours and Co. Inc. Wilmington, Del.);
perflurocyclobutane available under the tradename octafluoro cyclobutane (from PCR Gainsville, Fla.);
polyethylene glycol available under the tradename PEG 400 (from BASF Parsippany, N.J.);
menthol (from Pluess-Stauffer International Stanford, Conn.);
propylene glycol monolaurate available under the tradename lauroglycol (from Gattefossxc3xa9 Elmsford, N.Y.);
diethylene glycol monoethylether available under the tradename Transcutol (from Gattefossxc3xa9);
polyglycolized glyceride of medium chain fatty acids available under the tradename Labrafac Hydro WL 1219 (from Gattefossxc3xa9);
alcohols, such as ethanol, methanol and isopropanol;
eucalyptus oil (available from Pluess-Stauffer International); and mixtures thereof.
A surfactant optionally may be added to lower the surface and interfacial tension between the medicament and the propellant. Where the medicament, propellant and excipient are to form a suspension, a surfactant may or may not be required. Where the medicament, propellant and excipient are to form a solution, a surfactant may or may not be necessary, depending in part on the solubility of the particular medicament and excipient. The surfactant may be any suitable, non-toxic compound which is non-reactive with the medicament and which substantially reduces the surface tension between the medicament, the excipient and the propellant and/or acts as a valve lubricant. Among the preferred surfactants are:
oleic acid available under the tradename oleic acid NF6321 (from Henkel Corp. Emery Group, Cincinnati, Ohio);
cetylpyridinium chloride (from Arrow Chemical, Inc. Westwood, N.J.);
soya lecithin available under the tradename Epikuron 200 (from Lucas Meyer Decatur, Ill.);
polyoxyethylene (10) stearyl ether available under the tradename Briji 76 (from ICI);
polyoxyethylene (2) oleyl ether available under the tradename Brij 92 (from ICI);
polyoxyethylene-polypropylene-ethylenediamine block copolymer available under the tradename Tetronic 150 R1 (from BASF);
polyoxyethylene(20) sorbitan monolaurate available under the tradename Tween 20 (from ICI Specialty Chemicals, Wilmington, Del.);
polyoxyethylene(20) sorbitan monostearate available under the tradename Tween 60 (from ICI);
polyoxyethylene(20) sorbitan monooleate available under the tradename Tween 80 (from ICI);
polyoxypropylene-polyoxyethylene block copolymers available under the tradenames Pluronic L-92, Pluronic L-121 and Pluronic F 68 (from BASF);
castor oil ethoxylate available under the tradename Alkasurf CO-40 (from Rhone-Poulenc Mississauga Ontario, Canada); and mixtures thereof.
The medicaments of the present invention may include any pharmaceutically active compounds which are to be delivered by oral inhalation or nasally. Typical classes of compounds include bronchodilators, anti-inflammatory compounds, antihistamines, antiallergics, analgesics, antitussives, anti-anginal medications, steroids, corticosteroids, vasoconstrictors and antibiotics. Specific compounds within these classes of compounds are albuterol, mometasone furoate, beclomethasone dipropionate, isoproterenol, heparin, terbutaline, rimiterol, perbuterol, disodium cromoglycate, isoprenaline, adrenaline, pentamidine and ipratropium bromide. These compounds may be utilized either as the free base, as a salt, or as a clathrate depending upon the stablity and solubility of the active compound in the specific formulation. Where clathrates are utilized, P-11 and hexane clathrates are particularly preferred.
Where the active compound forms a suspension, the particle size should be relatively uniform, with substantially all the particles preferably ranging between about 0.1-25 microns, preferably 0.5-10 microns, more preferably 1-5 microns. Particles larger than 25 microns may be held up in the oropharyngeal cavity, while particles smaller than about 0.5 micron preferably are not utilized, since they would be more likely to be exhaled and, therefore, not reach the lungs of the patient.
The formulations of the present invention may be filled into the aerosol containers using conventional filling equipment. Since propellant 134a may not be compatible with all elastomeric compounds currently utilized in present aerosol valve assemblies, it may be necessary to substitute other materials, such as white buna rubber, or to utilize excipients and optionally surfactants which mitigate the adverse effects of propellant 134a on the valve components. One may optionally use an actuator device with a spacer to reduce force of the spray from an MDI.
To assure uniform dispersion of the active ingredient, the formulations typically will include the following components:
Depending on the particular application, the container may be charged with a predetermined quantity of formulation for single or multiple dosing. Typically, the container is sized for multiple-dosing, and, therefore, it is very important that the formulation delivered is substantially uniform for each dosing. For example, where the formulation is for bronchodilation, the container typically is charged with a sufficient quantity of the formulation for 200 charges.
Suitable suspensions may be screened in part by observing several physical properties of the formulation, i.e. the rate of particle agglomeration, the size of the agglomerates and the rate of particulate creaming/settling and comparing these to an acceptable standard. Suitable solutions may be screened by observing the solubility of the medicament over the entire recommended storage temperature range.
Suspensions of the present invention preferably may be prepared by either the pressure filling or cold filling procedures well-known in the art.
For metered dose inhalators, suspensions may be particularly preferred for efficacy and stability considerations.
Those skilled in the art may choose to add one or more preservative, buffer, antioxidant, sweetener and/or flavors or other taste masking agents depending upon the characteristics of the formulation.
Examples I-XXXII below further describe representative formulations of the present invention, some examples showing alternative formulations xe2x80x9cAxe2x80x9d and xe2x80x9cBxe2x80x9d.


The invention concerns a stent, in particular a coronary stent, comprising a tubular portion, wherein openings are provided in the tubular portion. The invention is distinguished in that the openings provided in the tubular portion of the stent are of a substantially T-shaped configuration.

Stents of that kind are known from the state of the art in many different forms. Those stents are used inter alia in connection with percutaneous transluminal angioplasty (PCTA, Percutaneous Transluminal Balloon Angioplasty), in vascular surgery of the heart. Stents however can also serve to dilate other openings in the body or to keep such openings in a dilated condition. That medical procedure is initially preceded by determining the location of the constriction in a coronary blood vessel. A so-called angioplasty balloon is then moved in the artery which has the constriction, the so-called stenosis, to the location of the stenosis where it is inflated. Due to the radially outwardly directed force of the inflated balloon the constriction is dilated and in the optimum case the original passage cross-section of the previously constricted artery is restored. Besides successful dilation of the vessel however side-effects can also occur, which include local splits in the artery, disintegration effects and projections of plate portions and flakes into the lumen of the artery so that, in spite of the dilation effect, blockage of the vessel can still occur. In addition it is possible that a stenosis can recur due to the vessel wall elastically springing back and/or due to the growth of the intima of the vessel. Statistically, that occurs within six months in the case of over 30% of the patients who were treated with PCTA.
In order now immediately after dilation of the vessel to ensure a relatively smooth inside wall surface for the vessel and to be able to avoid renewed stenosis, the stents set forth in the opening part of this specification were developed. Those small tubes serve inter alia in conjunction with PCTA to maintain the vessel flow cross-section which is produced by balloon angioplasty in order thereby to ensure long-term success with the PCTA procedure.
The success of such so-called stenting also depends inter alia on how uniformly the stent can come to bear against the wall of the vessel. For, the more uniformly the wall of the vessel is supported, the correspondingly more probable it is that vessel constrictions will not recur in the region of the stent. In that respect a regular stent structure produces a relatively smooth inside surface for the vessel and, with a relatively smooth inside vessel surface, blood particles can only be deposited thereon with difficulty. In addition growths of the intima into the interior of the vessel are prevented to a greater degree by a regular stent structure which covers over the inside surface of the vessel in a relatively closed configuration.
Stents of that kind with a so-called closed structure are also known from the state of the art. By way of example reference may be made here to one of the best-known stents of that kind, the so-called wall stent. That is known for example from U.S. Pat. No. 4,655,771. This stent which has a closed structure is formed from a plurality of wires which are regularly knitted in a mesh-like structure and which extend in a spiral configuration on the longitudinal axis of the stent.
The advantage of the closed structure of stents of that kind is however only achieved at the cost of the disadvantage that the stents involve relative longitudinal stiffness during insertion. Those stents do not therefore make it possible in the optimum manner for the stent to be guided through possibly very severely curved vessel portions in the coronary arteries upon insertion in a direction towards the stenosis to be treated. In order to avoid those disadvantages of a closed structure, stents have now been developed which are of a so-called modular nature. In the case of those stents of a modular nature, individual portions which are provided with a closed structure are connected together by flexible connections. Stents of that kind are known for example from U.S. Pat. No. 5,104,404.
A disadvantage with those modular or segmented stents however is that the front edges of each individual module or segment, which lead in the direction of insertion of the stent, can hook in the inside wall of the vessel. That can give rise to serious complications when inserting a stent. That is particularly problematical more especially insofar as the modular stentsxe2x80x94as already referred to abovexe2x80x94are used in particular when major curvatures have to be negotiated on the way to the location to be treated. For, it is in such a curve that such a leading edge of a segment becomes particularly easily hooked at the inside surface of the vessel, which is on the outside of the curvature, through which the stent is being passed.
Therefore the object of the invention is to avoid the above-mentioned disadvantages and to provide a stent of the kind set forth in the opening part of this specification which both permits the inside surface of the vessel to be covered in a closed configuration at the location of the stenosis to be treated while at the same time it is sufficiently flexible that it can be displaced to that location.
In the case of the present invention that object is attained by a stent of the kind set forth in the opening part of this specification, in that the openings provided in the stent are of a substantially T-shaped configuration.
The advantages of the invention are in particular that the T-shaped openings in the tubular structure of the stent provide a structure which is closed overall so as to provide for good covering of the lesion while at the same time by virtue of the T-shaped openings the flexibility in the longitudinal direction of the stent is increased in comparison with the closed stent structures which are known from the state of the art.
The invention involves the realization that the openings which are of a T-shaped configuration in accordance with the invention mean that those openings have two portions which extend substantially perpendicularly to each other. These involve on the one hand the portion of the opening, which forms the crossbar of the T-shape, and the portion of the opening, which forms the upright leg of the T-shape. In this case the crossbar of the T-shape preferably extends in the longitudinal direction of the tubular portion of the stent while the upright leg of the T-shape preferably extends in the peripheral direction of the tubular portion of the stent according to the invention. That configuration ensures that the stent has flexibility in both of the above-mentioned directions, such flexibility imparting to the stent according to the invention overall a degree of flexibility as is required for example when pushing the stent through curves in coronary blood vessels.
In a preferred configuration of the present invention the tubular portion has a peripheral surface, wherein the openings in the tubular portion are defined by bars, which bars are formed from the remaining material of a tube wall, forming the peripheral surface, of the tubular portion, the material having been removed from that tube wall in the region of the openings. This embodiment is distinguished in that the bars define the openings in the direction of the longitudinal axis of the tubular portion, substantially in the form of an S. This embodiment is advantageously distinguished in that an enhanced degree of flexibility of the stent is achieved by virtue of the S-shaped bars defining the openings, as the S-shape is inherently flexible. In addition, with this embodiment it is preferred if the S-shaped bars are arranged in such a way that the respective S-shape formed is disposed in the peripheral direction. For, in that way it is possible for the respective curve or bulge portions of the S-shape, upon insertion of the stent into curved coronary blood vessels, to be pushed into the adjacent bend configuration or the adjacent bulge portion of the same S-shape or the peripherally adjacent S-shape of the bars in order in that way to guarantee stent flexibility. A further advantage of this embodiment is that when crimping of the stent is effected a smaller crimp profile is produced. With this embodiment, that smaller crimp profile is made possible by the S-shaped bars without the bars touching each other. The smaller diameter of the crimp profile which can be achieved in that way facilitates access to stenoses and makes it easier to reach remote stenoses by means of such a stent.
In a further preferred embodiment of the invention the openings are of a mirror image-symmetrical configuration with respect to a peripheral line intersecting them. That configuration ensures that, upon being dilated, the stent expands uniformly without the stent structure suffering from being pulled askew upon expansion.
A further development of the invention is distinguished in that the bars define the openings in such a way that the parts of the T-shaped openings, which form the upright legs of the T-shape, extend substantially in the peripheral direction of the tubular portions. In that case, it is further preferred if the bars define the openings in such a way that the parts of the openings, which form the crossbars of the T-shaped openings, extend substantially in the longitudinal direction of the tubular portions of the stent. That regular arrangement of the bars provides for an optimally closed structure with its advantages as set forth in the opening part of this specification. At the same time however the openings which are of a T-shaped configuration in that way provide that the parts of the openings, which form the crossbar of the T-shape, are laterally movable in the optimum fashion, as is a considerable advantage for example when introducing the stent into severe curvatures in coronary blood vessels.
In a further preferred embodiment of the present invention the portions of the bars which form the ends of the S-shaped bars defining the openings in the longitudinal direction of the tubular portion are respectively connected by way of connecting means to the portions which form the corresponding ends and which are disposed in opposite relationship in mirror image-symmetry with respect to the T-shaped opening enclosed by the bars. In that respect it is preferred if the connecting means are bars extending substantially in the longitudinal direction of the tubular portion of the stent according to the invention. Those bars can further preferably be of a slightly curved configuration in a lateral direction in order to enhance the flexibility of the stent also in that region of the connecting means. Overall however this configuration according to the invention makes it possible to achieve optimum application to the overall structure of the stent, of the various forces which occur upon flexural movements of the tubular portion.
In a further preferred embodiment of the present invention the S-shaped bars are of an inwardly inverted configuration at at least one of the bulge portions of the S-shape. Those inwardly inverted portions which in a further preferred feature are inverted inwardly into the bulge configuration of the corresponding S-shape by at least 50% of said bulge configuration, make it possible in a particularly advantageous fashion to successfully avoid an axial reduction in the length of the stent upon radial expansion thereof. For, those inwardly inverted portions which are incorporated into the bulge-shaped regions of the S-shaped bars afford a radial expansion potential for the stent, without that being at the expense of the length of the stent. In addition those inwardly inverted portions also provide for a further increase in the flexibility of the stent as those curve portions further increase the lateral mobility of the S-shaped bars.
These structures, which are also to be referred to as a double curve, consisting of S-shaped bars and inwardly inverted portions in the bulge portions of the S-shaped bars, therefore serve in a quite particular fashion to attain the object of the invention.
In a further development of the stent according to the invention the part of the opening, which forms the crossbar of the T-shape, is wider than the part forming the upright leg of the T-shape. By means of this embodiment it is advantageously possible for the stent also to be fitted in the region of vessel branchings in a procedure for stenting coronary blood vessels. With this embodiment it is an easy matter to incorporate windows into a design of this kind. For, by virtue of the closed, homogenous and regular structure, such a windowing configuration for a given region of the tubular portion of the stent according to the invention does not have a detrimental effect on the strength of the overall structure. That is also afforded inter alia by the interleaving relationship of the T-shaped openings. For, that interleaving configuration in turn provides that the peripheral surface of the stent is in particular uniformly covered in the expanded condition so that, when the stent is in the expanded condition, no relatively large interconnected free areas remain open in the peripheral surface. Accordingly the closed homogenous stent structure according to the invention is not only found to be more flexible in comparison with the known state of the art in respect of closed structures of that kind; on the contrary, by means of that structure, it is also readily possible to provide windows for a vessel branching in the stent. For, window configurations of that kind are not readily possible in the state of the art with the previously known closed structures as they are excessively tightly structured, that is to say they do not afford adequate options in terms of providing and incorporating a window of that kind.
A further advantage of the interleafing arrangement as already referred to above becomes clear when considering the cross-section of the expanded stent, that is to say when considering it in the axial direction. For, the deformable T-shaped elements of the stent according to the invention are further divided by the above-mentioned inwardly inverted portions extending into the bulge configurations of the S-shaped bars. The consequence of this is that the stent is constructed generally and in particular in the peripheral direction from comparatively short bars. Therefore the bars defining the T-shaped openings have only relatively short straight bar portions. As however upon expansion of the stent the deformation of the bars occurs in particular in the region of the radii, that is to say the curves in the bars, the stent according to the invention involves an approximation of the expanded stent cross-section to a circular shape in a particular fashion. That improves the adaptability of the stent according to the invention to the surrounding vessel, in comparison with the stent known from the state of the art. For, the known stents to be found in the state of the art have only relatively long bar segments which only insufficiently approach a circular shape upon expansion of the stent in respect of the stent cross-section. In the state of the art therefore there is the disadvantage that individual bar portions, in the expanded stent, project into the interior of the vessel and thus disadvantageously impede the free flow of blood therethrough.
A particularly preferred embodiment of the invention is distinguished in that all openings are of the same size. The stent is accordingly preferably constructed from regularly repeating, always identical structural elements or so-called unit cells.
Further preferred embodiments of the invention are set forth in the appendant claims.

Biotronik Mess- und Therapiegeraete GmbH and Co. Ingenieurbuero Berlin