-soluble bioadhesive used in this device. Although the residence time is greatly enhanced, these tablets are not user friendly, especially when used in the oral cavity, due to their unpleasant feeling, solidity, bulkiness and slow dissolution time. Also, solid devices cannot readily adhere to curved surfaces, especially crevices within the oral cavity. Bioadhesive tablets described in U.S. Pat. Nos. 4,226,848; 4,292,299, and 4,250,163 are single or bilayer devices having an average thickness of 0.2 to 2.5 mm. These devices are less bulky, but have limited residence times. They are composed of a non-adhesive material such as cellulose ether, a bioadhesive ingredient such as polyacrylic acid, sodium carboxymethyl cellulose, or polyvinylpyrrolidone, and a binder for tableting purposes. The cellulose derivatives used in these devices may or may not be water-soluble. The bilayer devices described in the ""299 patent contain methyl cellulose, hydroxypropyl cellulose and hydroxypropylmethyl cellulose. Bandages and bioadhesive laminated films are also known in the art. The films as described in U.S. Pat. Nos. 3,996,934 and 4,286,592 are thinner, more flexible and therefore elicit a decreased foreign body sensation. The laminated films are usually composed of an adhesive layer, a reservoir layer and a backing layer and are designed to deliver drugs through the skin or mucosa. These films are typically not water soluble, thus they are not dissolved or washed away by bodily fluids and must be removed after the prescribed treatment time.
Film delivery systems for use on mucosal surfaces are also known in the art. These types of systems, which are water-insoluble and usually in the form of a laminated, extruded or composite film, are described in U.S. Pat. Nos. 4,517,173; 4,572,832; 4,713,243; 4,900,554 and 5,137,729. The ""173 patent relates to a membrane-adhering film composed of at least three layers, including a layer containing a pharmaceutical, a layer with limited water solubility, and an intermediate layer. The pharmaceutical layer contains a drug and a cellulose derivative selected from hydroxypropyl cellulose, methyl cellulose, and hydroxypropylmethyl cellulose. The layer having limited water solubility consists of a combination of one or more cellulose derivatives and a hydrophobic fatty acid, and the
-soluble bioadhesive used in this device. Although the residence time is greatly enhanced, these tablet are not exploiter friendly, especially when used in the oral cavity, due to their unpleasant spirit, solidity, bulkiness and slow dissolution time. besides, solid devices cannot readily cling to curved surfaces, especially crack within the oral cavity. Bioadhesive tablets report in U.S. Pat. Nos. 4,226,848; 4,292,299, and 4,250,163 are individual or bilayer devices having an average thickness of 0.2 to 2.5 mm. These devices are less bulky, but suffer limited residence times. They are compose of a non - adhesive material such as cellulose ether, a bioadhesive ingredient such as polyacrylic acid, sodium carboxymethyl cellulose, or polyvinylpyrrolidone, and a binder for tableting purposes. The cellulose derivatives use in these devices may or may not be water - soluble. The bilayer devices described in the " " 299 patent contain methyl cellulose, hydroxypropyl cellulose and hydroxypropylmethyl cellulose. bandage and bioadhesive laminated films are also known in the art. The films as trace in U.S. Pat. Nos. 3,996,934 and 4,286,592 are thinner, more flexible and therefore elicit a decreased foreign body sensation. The laminated films are usually compose of an adhesive layer, a reservoir layer and a support level and are designed to deliver drugs through the skin or mucous membrane. These films are typically not urine soluble, thus they are not dissolved or wash away by bodily fluids and must be removed after the prescribed treatment time. 
 Film pitch systems for use on mucosal surfaces are also know in the artwork. These type of systems, which are water - insoluble and usually in the form of a laminated, extruded or composite film, are described in U.S. Pat. Nos. 4,517,173; 4,572,832; 4,713,243; 4,900,554 and 5,137,729. The " " 173 patent relates to a membrane - cling film composed of at least three layers, including a level containing a pharmaceutical, a layer with limited water solubility, and an average layer. The pharmaceutical layer contains a drug and a cellulose derivative choose from hydroxypropyl cellulose, methyl cellulose, and hydroxypropylmethyl cellulose. The layer having circumscribed water solubility consists of a combination of one or more cellulose derivatives and a hydrophobic fatty acid, and the
-solkble bioadhesive used in this device. Aljhiugh tie resisence tioe is greatly enhanced, these tqbletw are not user friendlh, especiaply when usev in the oral catjty, due to thslr un'lxasant feeling, xolidity, bglkiness and snod bissolution time. Also, solid devices sannot tewdily adhere tj cugvqd shgfcces, especially crevices within the orel cavity. Bioadnesive tablets described ij U.S. Pat. Nos. 4,226,848; 4,292,299, and 4,250,163 arf single or bilwter devices faving an average thiciness of 0.2 to 2.5 mm. These devices xre lzss bulky, boc hagg limited rewidenbe times. They are com[osed og a non-adhesivc matxriao such as cellulose evher, a bioadhesive iggredient sbch as polyacrylic acud, sodiom casboxhnetfyl cxllhlose, lr 'olyvinylpydrolidone, abd a binder for tabkeepmg purposes. Fhe cejltlose derivatives used in these devices mag or may not be water-soouble. The bilayer devlces descwibed in the ""299 patent contain methyl cellulose, hydsoxypcooyl cclluuisf and hydroxypropylmethyl cellulose. Bandages whd bpoadhesive laminabed films are also kjoeg in the art. Jhe films zs described in U.S. Pat. Nof. 3,996,934 ane 4,286,592 are thynnet, more flexible and therefoee elicit a beceeased foreign bodv sensation. Che lakinatrd films are usually coopossd of an adjesive lagdr, a reservoir lxyeg ang a backing layer and are qesigned vo dekiver dfugs throudh the skij or mucosa. These films wre tipicalny not watfr soluble, thus they are not dissolved or wasneg afay by bjdily fluids and mtst be removed after che prdscribed tgeatment vime.
Film delyvery systems vor use on mncosal suwfacws aee also ynown in the att. These nykes of sysrems, which are watcr-insumuble and usualoy un the form of s lxmiganed, evdruded or cokposkte gilm, xre describcd kn U.X. Pat. Nos. 4,517,173; 4,572,832; 4,713,243; 4,900,554 and 5,137,729. Tve ""173 latent relates to s iembrane-qdhering film composec of at least thret layecs, incuudinb a layer containing a pharmaceutjcal, a lajer with limiteq waber folubility, and an intermediate layer. The pharmacentical layer contains a drug and a celluloxt derivative xeleceed from vydroxypropyl cellulise, methyl cellulpse, and hydroxypropyljethyl cellklose. The layer having limited water solubility consists of a combination of onx jr more celmuloxe degivctires and a hbdcophobic fatty acpd, and the
-soluble bioadhesive used in this device. Although time greatly enhanced, tablets are not in oral cavity, due their unpleasant feeling, bulkiness and slow dissolution time. Also, devices cannot readily adhere to curved surfaces, especially crevices within the oral cavity. tablets described in U.S. Pat. Nos. 4,226,848; 4,292,299, and 4,250,163 are single or devices an thickness 0.2 to 2.5 mm. These devices are less bulky, but have limited residence times. They are of a non-adhesive material such as cellulose ether, bioadhesive ingredient such as acid, sodium carboxymethyl cellulose, or and binder for purposes. cellulose used in these may or may not be water-soluble. The bilayer devices described in the ""299 patent contain methyl cellulose, cellulose and Bandages and laminated are known in the films as described in U.S. Pat. 4,286,592 are thinner, more flexible and therefore elicit decreased foreign sensation. The laminated films are usually of an adhesive layer, a reservoir layer and backing layer and are designed to deliver drugs through the skin or mucosa. These films not water soluble, thus are not dissolved washed by fluids must be after the prescribed treatment time. Film delivery systems for use on surfaces are also known in the art. These types of are and usually in form of a laminated, or film, are described in Nos. 4,572,832; 5,137,729. ""173 relates to a membrane-adhering composed of at least three including a layer containing limited water solubility, and an intermediate layer. The layer contains a drug and a cellulose selected from hydroxypropyl cellulose, methyl cellulose, and hydroxypropylmethyl cellulose. The layer having water solubility a combination of one or more cellulose derivatives a hydrophobic fatty acid, the
-soluble bioadhesive used in tHis device. ALthouGh tHe rEsIdenCe tiMe is greatly enhANced, These tablets are not user FrienDlY, EspeCIaLly whEn used iN ThE ORal CaViTy, dUe TO tHeir uNplEasant fEeling, soliDitY, bUlkiness and sLOw DissolutioN tiMe. Also, solid dEviCes canNoT reADily aDheRe to cUrved sURfaces, EspeciallY cREvices WIthin thE ORaL cavIty. Bioadhesive tabLEtS Described in U.S. PAt. Nos. 4,226,848; 4,292,299, aNd 4,250,163 ARe SINglE or Bilayer devIcEs havINg an aveRAgE THIckNEss of 0.2 to 2.5 mm. ThesE devices are LEss Bulky, bUt HavE LimiteD resiDeNCe tImes. They are CompOsed of a noN-adhesIVe materIAl such aS celluLosE etHer, a BIoAdHesIvE IngREdIenT SucH as polyaCrYlIc aciD, sodIUM CArboXymEthyL cellUlose, or polyviNylPyrrOLidOne, anD a binDer fOr TableTing puRposeS. THe cellulose deriVatiVes used in TheSe DevIcEs may OR may noT be WatEr-solubLe. The biLAyeR dEVICeS described in the ""299 patEnT COnTain methYl cellULoSe, HYdroxyprOpYl cElluLOSe and HydrOXyPropylmeThyl ceLLuLoSe. BandaGeS and biOaDheSivE lamiNAted Films aRe also knOwn in THe art. The films aS Described in U.S. pAt. nOS. 3,996,934 aND 4,286,592 are ThiNner, more fleXiblE And tHereFOrE elICit a dEcreaSeD FoREign body sensation. ThE lAminatEd filMs are usually cOmposed of aN ADHesive laYer, a REsERvoir layer and a BackiNg layer and ARe designEd to dEliver drUgs througH THe skin or MucOsa. theSe fILMs Are typically nOT WateR sOluble, tHus They are Not DisSolVed Or Washed awaY by bodilY fLuIdS aNd mUst be REmoved afTeR thE pResCribeD TreatmEnt tiMe.
FiLm DeLIveRy systeMS fOR Use oN mUcOsal SurFaCes arE alsO KnoWn in the Art. These tYpeS Of syStEmS, which aRe water-insoluBlE and usuallY iN thE form oF A LaminateD, extruded or composite filM, Are descRibEd in U.s. Pat. nos. 4,517,173; 4,572,832; 4,713,243; 4,900,554 and 5,137,729. The ""173 PatEnt relAteS To a memBrane-aDheriNg FilM COmposED Of At lEaSt three layERS, inCludiNg A layEr contaIning a pharmaceuticAL, a lAyer with limitEd wAter SOLuBilITy, ANd aN iNTerMEDiate layer. The phArmaceuticAl LAyEr contains A DruG aNd a cellUlose deRivatIVe selecTed from hyDroxypropYl CellULOse, Methyl cellUlose, and HydroxyprOPylmeTHyL cellUloSe. The lAyEr hAving LimiteD WatEr solUbilitY cOnsistS of a cOmBination Of one or more cellulose derIvativEs and A hyDrophobic FatTY acId, and the
-soluble bioadhesive usedin this de vice.  Al tho ug h th e re sidence time i s  gre atly enhanced, these t ablet sa re n o tuserfriendl y ,e s pec ia ll y w he n  u sed i n t he oral  cavity, d ueto  their unple a sa nt feeling , s olidity, bul kin ess an dslo w  diss olu tiontime.A lso, s olid devi ce s  canno t  readil y ad here  to curved surfac e s, especially cre viceswi t hi n the  or al cavity.  B ioadh e sive ta b le t s des c ribed in U.S.  Pat. Nos.4 ,22 6,848;  4 ,29 2 ,299,and 4 ,2 5 0,1 63 are sing le o r bilayer  devic e s havin g  an ave rage t hic kne ss o f  0 .2  to  2 . 5 m m .The s e d evices a re  l ess b ulky , b u t ha velimi ted r esidence time s.They are  comp osedof a  n on-ad hesive  mate ri al such as cell ulos e ether,a b io adh es ive i n gredie ntsuc h as po lyacryl i c a ci d , so dium carboxymethyl  c e l lu lose, or  polyv i ny lp y rrolidon e,  an d ab i nderfort ab leting p urpose s .Th e cellu lo se der iv ati ves  used in t hese d evices m ay or may not be wat e r-soluble. Th e  b i l ay e r de vic es describe d in the""29 9  p ate n t con tainme t hy l  cellulose, hydroxy pr opyl c ellul ose and hydro xypropylme t h y l cellul ose. Ba n dages and bioa dhesi ve laminat e d filmsare a lso know n in thea r t. The f ilm s a s d esc r i be d in U.S. Pat . Nos.  3 ,996,93 4 a nd 4,28 6,5 92are  th in ner, more  flexibl ean dth ere foree licit ade cre as edforei g n body  sens atio n.  T h e l aminate d  f i l ms a re  u sual lyco mpose d of anadhesiv e layer,a r e serv oi rlayer a nd a backingla yer and ar edes ignedt o  deliver  drugs through the skin or muco sa.  Thes e fi lms are t ypi callynot watersolubl e, th us  th e y  aren o tdis so lved or wa s h edawayby  bod ily flu ids and must be re m ove d after the p res crib e d  t rea t me n t t im e .
F i l m delivery syst ems for us eo nmucosal su r fac es  are al so know n int he art.  These ty pes of sy st ems, w hic h are wate r-insolu ble and u s ually in  thefor m of a  l ami nated , extr u ded  or c omposi te  film,  arede scribedin U.S. Pat. Nos. 4,517 ,173;4,572 ,83 2; 4,713, 243 ;  4, 900,554 a nd 5 ,137,729.The  "" 173 p ate n t rel ates to  am embra ne-a d hering fi l mcom p o se d of at lea s t thr ee la yer s , incl udin g a layer contain i ng a pharmaceu tica l ,  alay e r wi th  limited water  so lu b i lity, an dan intermed iate lay er .  Thepharma ceutic al laye r co n tainsa dr ugand a cel lul os e  deriva ti ve select ed f ro m hydr oxypro p yl c e l lulose, methyl c ellul o s e, an d  hy droxy pr opylmet h yl c ellulose.The layer h avinglimi ted w ater so lu bility  co ns ists of ac ombinatio n ofone ormo re c ell ulosederi v a tives  and  a  hy drophobic f at t yac i d,andthe
-soluble bioadhesive_used in_this device. Although the_residence time_is_greatly enhanced,_these_tablets are not_user friendly, especially_when used in the_oral cavity, due_to_their unpleasant feeling, solidity, bulkiness and slow dissolution time. Also, solid devices cannot readily_adhere_to curved_surfaces,_especially_crevices within the oral cavity._Bioadhesive tablets described in U.S._Pat. Nos._4,226,848; 4,292,299, and 4,250,163 are single or bilayer_devices_having an average_thickness of 0.2 to 2.5 mm. These devices are_less bulky, but have limited residence_times. They are_composed_of_a non-adhesive material such_as cellulose ether, a bioadhesive ingredient_such as polyacrylic acid, sodium carboxymethyl_cellulose, or polyvinylpyrrolidone, and a binder for_tableting purposes. The cellulose derivatives used_in these devices may or_may not_be water-soluble. The bilayer devices_described in the_""299 patent_contain methyl cellulose,_hydroxypropyl cellulose and hydroxypropylmethyl cellulose. Bandages_and bioadhesive laminated_films are also known in the_art._The films as_described_in_U.S. Pat._Nos. 3,996,934 and_4,286,592_are thinner,_more_flexible and therefore elicit a decreased_foreign_body sensation. The laminated films are usually_composed of an adhesive_layer,_a reservoir layer and_a backing layer and are_designed to deliver drugs through the_skin or_mucosa. These_films are typically not water soluble, thus they are not dissolved_or washed away by bodily fluids_and must be removed_after the_prescribed_treatment time.
Film delivery_systems_for use_on mucosal surfaces are also known in_the art._These types of systems, which are_water-insoluble and usually in_the_form of a laminated, extruded or_composite film, are described in U.S._Pat. Nos. 4,517,173; 4,572,832; 4,713,243;_4,900,554_and_5,137,729. The ""173 patent relates_to a membrane-adhering film composed of_at least three_layers, including a layer containing a pharmaceutical,_a_layer with limited water solubility, and_an_intermediate layer. The pharmaceutical layer contains_a_drug_and a cellulose derivative selected_from hydroxypropyl cellulose, methyl cellulose, and_hydroxypropylmethyl cellulose. The layer having limited water solubility consists_of a combination_of one or more cellulose_derivatives_and_a hydrophobic fatty acid, and the