as used herein and in the claims , the term “ fast dispersing dosage form ( fddf )” refers to compositions which disintegrate / disperse within 1 to 60 seconds , preferably 1 to 30 seconds , more preferably 1 to 10 seconds and particularly 2 to 8 seconds , of being placed in the oral cavity . the dosage form of the present invention is similar to the dosage forms described in u . k . pat . no . 1548022 , that is , a solid fast dispersing dosage form comprising a network of the active ingredient and a water - soluble or water - dispersible carrier , which is inert towards the active ingredient , the network having been obtained by subliming solvent from a composition in the solid state , that composition comprising the active ingredient and a solution of the carrier in a solvent . the point of distinction being that the modified starch is used as the carrier in place of the conventional mammalian gelatin . the fast dispersing dosage form according to the invention may also contain , in addition to the active ingredient and modified starch , other matrix forming agents and secondary components . matrix forming agents suitable for use in the present invention include materials derived from animal or vegetable proteins , such as non - mammalian gelatins , dextrins and soy , wheat and psyllium seed proteins ; gums such as acacia , guar , agar , and xanthan ; polysaccharides ; alginates ; carboxymethylcelluloses ; carrageenans ; dextrans ; pectins ; synthetic polymers such as polyvinylpyrrolidone ; and polypeptide / protein or polysaceharide complexes such as gelatin - acacia complexes . matrix forming agents suitable for use in the present invention include sugars such as mannitol , dextrose , lactose , galactose and trehalose ; cyclic sugars such as cyclodextrin ; inorganic salts such a s s odium phosphate , sodium chloride and aluminum silicates ; and amino acids having from 2 to 12 carbon atoms such as a glycine , l - alanine , l - aspartic acid , l - glutamic acid , l - hyd roxyprsline , l - isoleucine , l - leucine and l - phenylalanine . one or m ore matrix forming agents may be incorporated into the solution or suspension prior to solidification . the matrix forming agent may be present in addition to a surfactant or to the exclusion of a surfactant . in addition to forming the matrix , the matrix forming agent may aid in maintaining the dispersion of any active ingredient within the solution , suspension or mixture . this is especially helpful in the case of active agents that are not sufficiently soluble in water and must , therefore , be suspended rather than dissolved . secondary components such as preservatives , antioxidants , surfactants , viscosity enhancers , coloring agents , flavoring agents , ph modifiers , sweeteners or taste - masking agents may also be incorporated into the composition . suitable coloring agents include red , black and yellow iron oxides and fd & amp ; c dyes such as fd & amp ; c blue no . 2 and fd & amp ; c red no . 40 . suitable flavoring agents include mint , raspberry , licorice , orange , lemon , grapefruit , caramel , vanilla , cherry and grape flavors and combinations of these . suitable ph modifiers include citric acid , tartaric acid , phosphoric acid , hydrochloric acid , maleic acid and sodium hydroxide . suitable sweeteners include aspartame , acesulfame k and thaumatin . suitable taste - masking agents include sodium bicarbonate , ion - exchange resins , cyclodextrin inclusion compounds , adsorbates or microencapsulated actives . in general the modified starch will comprise from 5 % to 99 . 5 % by weight solids of the fddf , normally 20 % to 90 %, usually 50 to 90 %. any drug may be used as the active ingredient in the composition of the present invention . examples of suitable drugs include but are not limited to those listed below : analgesics and anti - inflammatory agents : aloxiprin , auranofin , azapropazone , benorylate , diflunisal , etodolac , fenbufen , fenoprofen calcim , flurbiprofen , ibuprofen , indomethacin , ketoprofen , meclofenamic acid , mefenamic acid , nabumetone , naproxen , oxaprozin , oxyphenbutazone , phenylbutazone , piroxicam , sulindac . anthelmintics : albendazole , bephenium hydroxynaphthoate , cambendazole , dichlorophen , ivermectin , mebendazole , oxamniquine , oxfendazole , oxantel embonate , praziquantel , pyrantel embonate , thiabendazole . anti - bacterial agents : benethamine penicillin , cinoxacin , ciprofloxacin hcl , clarithromycin , clofazimine , cloxacillin , demeclocycline , doxycycline , erythromycin , ethionamide , imipenem , nalidixic acid , nitrofurantoin , rifampicin , spiramycin , sulphabenzamide , sulphadoxine , sulphamerazine , sulphacetamide , sulphadiazine , sulphafurazole , sulphamethoxazole , sulphapyridine , tetracycline , trimethoprim . anti - epileptics : beclamide , carbamazepine , clonazepam , ethotoin , methoin , methsuximide , methylphenobarbitone , oxcarbazepine , paramethadione , phenacemide , phenobarbitone , phenytoin , phensuximide , primidone , sulthiame , valproic acid . anti - fungal agents : amphotericin , butoconazole nitrate , clotrimazole , econazole nitrate , fluconazole , flucytosine , griseofulvin , itraconazole , ketoconazole , miconazole , natamycin , nystatin , sulconazole nitrate , terbinafine hcl , terconazole , tioconazole , undecenoic acid . anti - hypertensive agents : amlodipine , benidipine , darodipine , dilitazem hcl , diazoxide , felodipine , guanabenz acetate , indoramin , isradipine , minoxidil , nicardipine hcl , nifedipine , nimodipine , phenoxybenzamine hcl , prazosin hcl , reserpine , terazosin hcl . anti - malarials : amodiaquine , chloroquine , chlorproguanil hcl , halofantrine hcl , mefloquine hcl , proguanil hcl , pyrimethamine , quinine sulphate . anti - migraine agents : dihydroergotamine mesylate , ergotamine tartrate , methysergide maleate , pizotifen maleate , sumatriptan succinate . anti - muscarinic agents : atropine , benzhexol hcl , biperiden , ethopropazine hcl , hyoscine butyl bromide , hyoscyamine , mepenzolate bromide , orphenadrine , oxyphencylcimine hcl , tropicamide . anti - neoplastic agents and immunosuppressants : aminoglutethimide , amsacrine , azathioprine , busulphan , chlorambucil , cyclosporin , dacarbazine , estramustine , etoposide , lomustine , melphalan , mercaptopurine , methotrexate , mitomycin , mitotane , mitozantrone , procarbazine hcl , tamoxifen citrate , testolactone . anti - protazoal agents : benznidazole , clioquinol , decoquinate , diiodohydroxyquinoline , diloxanide furoate , dinitolmide , furzolidone , metronidazole , nimorazole , nitrofurazone , omidazole , tinidazole . anxiolytic , sedatives , hypnotics and neuroleptics : alprazolam , amylobarbitone , barbitone , bentazepam , bromazepam , bromperidol , brotizolam , butobarbitone , carbromal , chlordiazepoxide , chlormethiazole , chlorpromazine , clobazam , clotiazepam , clozapine , diazepam , droperidol , ethinamate , flunanisone , flunitrazepam , fluopromazine , flupenthixol decanoate , fluphenazine decanoate , flurazepam , haloperidol , lorazepam , lormetazepam , medazepam , meprobamate , methaqualone , midazolam , nitrazepam , oxazepam , pentobarbitone , perphenazine pimozide , prochlorperazine , sulpiride , temazepam , thioridazine , triazolam , zopiclone . corticosteroids : beclomethasone , betamethasone , budesonide , cortisone acetate , desoxymethasone , dexamethasone , fludrocortisone acetate , flunisolide , flucortolone , fluticasone propionate , hydrocortisone , methylprednisolone , prednisolone , prednisone , triamcinolone . diuretics : acetazolamide , amiloride , bendrofluazide , bumetanide , chlorothiazide , chlorthalidone , ethacrynic acid , frusemide , metolazone , spironolactone , triamterene . gastro - intestinal agents : bisacodyl , cimetidine , cisapride , diphenoxylate hcl , domperidone , famotidine , loperamide , mesalazine , nizatidine , omeprazole , ondansetron hcl , ranitidine hcl , sulphasalazine . histamine h ,- receptor antagonists : acrivastine , astemizole , cinnarizine , cyclizine , cyproheptadine hcl , dimenhydrinate , flunarizine hcl , loratadine , meclozine hcl , oxatomide , terfenadine , triprolidine . nitrates and other anti - anginal agents : amyl nitrate , glyceryl trinitrate , isosorbide dinitrate , isosorbide mononitrate , pentaerythritol tetranitrate . opioid analgesics : codeine , dextropropyoxyphene , diamorphine , dihydrocodeine , meptazinol , methadone , morphine , nalbuphine , pentazocine . oral vaccines : vaccines designed to prevent or reduce the symptoms of diseases of which the following is a representative but not exclusive list : influenza , tuberculosis , meningitis , hepatitis , whooping cough , polio , tetanus , diphtheria , malaria , cholera , herpes , typhoid , hiv , aids , measles , lyme disease , travellers diarrhea , hepatitis a , b and c , otitis media , dengue fever , rabies , parainfluenza , rubella , yellow fever , dysentery , legionnaires disease , toxoplasmosis , q - fever , haemorrhegic fever , argentina haemorrhagic fever , caries , chagas disease , urinary tract infection caused by e . coli , pneumoccoccal disease , mumps , and chikungunya . vaccines to prevent or reduce the symptoms of other disease syndromes of which the following is a representative but not exclusive list of causative organisms : vibrio species , salmonella species , bordetella species , haemophilus species , toxoplasmosis gondii , cytomegalovirus , chlamydia species , streptococcal species , norwalk virus , escherischia coli , helicobacter pylori , rotavirus , neisseria gonorrhae , neisseria meningiditis , adenovirus , epstein barr virus , japanese encephalitis virus , pneumocystis carini , herpes simplex , clostridia species , respiratory syncytial virus , klebsielia species , shigella species , pseudomonas aeruginosa , parvovirus , campylobacter species , rickettsia species , varicella zoster , yersinia species , ross river virus , j . c . virus , rhodococcus equi , moraxella catarrhalis , borrelia burgdorferi and pasteurella haemolytica . vaccines directed to non - infections immuno - modulated disease conditions such as topical and systematic allergic conditions such as hayfever , asthma , rheumatoid arthritis and carcinomas . vaccines for veterinary use include those directed to coccidiosis , newcastle disease , enzootic pneumonia , feline leukaemia , atrophic rhinitis , erysipelas , foot and mouth disease , swine , pneumonia , and other disease conditions and other infections and auto - immune disease conditions affecting companion and farm animals . proteins , peptides and recombinant drugs : insulin ( hexameric / dimeric / monomeric forms ), glucagon , growth hormone ( somatotropin ), polypeptides or their derivatives , ( preferably with a molecular weight from 1000 to 300 , 000 ), calcitonins and synthetic modifications thereof , enkephalins , interferons ( especially alpha - 2 interferon for treatment of common colds ), lhrh and analogues ( nafarelin , buserelin , zolidex ), ghrh ( growth hormone releasing hormone ), secretin , bradykin antagonists , grf ( growth releasing factor ), thf , trh ( thyrotropin releasing hormone ), acth analogues , igf ( insulin like growth factors ), cgrp ( calcitonin gene related peptide ), atrial natriurectic peptide , vasopressin and analogues ( ddavp , lypressin ), factor viii , g - csf ( granulocyte - colony stimulating factor ), epo ( erythropoitin ). sex hormones : clomiphene citrate , danazol , ethinyloestradiol , medroxyprogesterone acetate , mestranol , methyltestosterone , norethisterone , norgestrel , oestradiol , conjugated oestrogens , progesterone , stanozolol , stiboestrol , testosterone , tibolone . the precise quantity of active ingredient will depend on the drug selected . however , the active ingredient is generally present in an amount from 0 . 2 to 95 %, normally 1 to 20 %, by weight of the composition of the dried dosage form . the invention is further illustrated by the following examples which are intended to be illustrative and not limitative . in the following examples fddf were prepared and tested in absence of an active ingredient . amylogum cls is a starch whose hydroxyl groups have been esterified . it is commercially available from the avebe u . k ., ltd . of south huberside , england . the mannitol was supplied by roquette ltd . of kent , england . the starch was added to the purified water and heated to 60 ° c . while stirring . the resulting mix was maintained at 60 ° c . for 10 minutes to effect solution and subsequently cooled to ambient temperature . when the mix had sufficiently cooled , the mannitol was added and stirred until fully dissolved . the mix was dosed into pvc / pvdc blisters with 500 mg fill weights . units were frozen in a stream of cold nitrogen gas then freeze dried by ramping from − 10 ° c . to + 20 ° c . at a pressure of 0 . 5 mbar . the following formulation was prepared adopting the procedure of example 1 . perfectagel mpt is a hydroxypropyl distarch phosphate and is commercially available from avebe u . k ., ltd . paselli md 10 is an enzymatically modified starch and is commercially available from avebe u . k . ltd . the water was stirred with a hand - held electronic mixer and the starch and mannitol added , while stirring . no heating was required for this starch . the solution was left stirring for 1 . 5 hours to equilibrate . dispersion of the dosage forms in the mouth was smooth , rapid and had a sweet taste . the following formulation was prepared adapting the procedure of example 3 . avebe md20 is an enzymatically modified starch commercially available from avebe u . k ., ltd . the dosage forms prepared in examples 1 to 4 all gave rapid disintegration times in the mouth of less than 10 seconds . all of these modified starches are commercially available from avebe , u . k ., ltd . powders were dry - blended and added to the vortex of the purified water . the mixes subsequently being heated to 50 ° c . and then homogenized with a silverson l4r ( small head adapter ). batches were allowed to cool to ambient temperatures , while continually stirring . viscosity measurements were taken after 1 to 3 hours mixing and after 22 hours , using the haake viscometer at 500 xs − 1 . no significant change in viscosity was observed over a 22 hour period . this is a highly desirable property in the preparation of fddf &# 39 ; s . this property improves the efficiency of production and reduces loses due to waste . paselli bc is a pre - gelatinized acetylated di - starch phosphate commercially available from croda colloids , ltd . of cheshire , england . gelatin formulation the gelatin and mannitol were added to the vortex of the purified water , and heated to 60 ° c . to effect solution . the mix was subsequently cooled to 25 ° c . prior to dosing . the mannitol and paselli bc were dry - mixed and then gradually added to the vortex of the purified water , at ambient temperatures . the resultant mix was subsequently homogenized using the silverson l4r ( small head adapter ) for approximately 1 minute . mixes were dosed into pvc / pvdc , 16 mm diameter , 500 mg fill weight blisters using the programmable hamilton microlab m dispenser . blisters were frozen in a stream of cold nitrogen gas before freeze drying by ramping from − 10 ° c . to + 20 ° c . at a pressure of 0 . 5 mbar . units were placed , unsealed , in stability cabinets at 40 ° c . with a relative humidity of 75 % for 20 hours , the diameters of the units being taken after this time . it can be seen that the fddf using the modified starch had a 50 % decrease in the amount of shrinkage over the conventional fddf containing gelatin . this is an unexpected and surprising result . an article entitled “ drug delivery products and the zydis fast dissolving dosage form ” by h . seagers et al ., j pharm pharmacol . 1998 , discusses the problems associated with highly water soluble drugs in a fddf . zydis ® is the registered trademark of the r . p . scherer corporation , basking ridge , n . j ., usa . seagers et al . recognize that the dose of water soluble drugs is generally limited to an upper value of about 60 mg per dosage form . the dose is governed by the behavior of the drug during the freezing process and on its drying characteristics . eutectic mixtures can be formed which may not adequately freeze or might melt at the higher temperatures used in the freeze drying process . it is also possible that the dissolved drug could form an amorphous solid on freezing and that this solid might collapse during the drying process due to sublimation of ice and loss of supporting structure . the collapse of the structure formed by the water soluble drugs is known to be lessened by the inclusion of a crystal forming excipient . these materials are sometimes also known as matrix forming agents . these materials induce crystallinity and hence rigidity in the amorphous products . another approach is to bind the water soluble compound to an ion exchange resin to form a water insoluble complex . a further technique is to dose a non - aqueous solution of the active ingredient onto pre - formed placebo fddf units . the organic solvent is then evaporated and the re - crystallized drug is deposited in the pores of the zydis matrix . another technique known to overcome this problem of high water soluble actives is to reduce the drug to excipient ratio and thereby increase the blister fill weight . this effectively dilutes the affect of the soluble active , by having the same drug dose , but a greater quantity of excipients being present . this potential solution has obvious disadvantages in that it requires greater quantities of excipients , a larger “ less patient friendly ” dosage form , and a decrease in throughput in the manufacture due to size limitations . it has also been known that the solubility of a drug can be changed through manipulation of the ph . reduced solubility is known to facilitate incorporation of a higher dose of the active in a fddf . one aspect of the present invention resides in the discovery that the use of an essentially gelatin free fddf which utilizes a modified starch material , can incorporate higher levels of water soluble drugs than the conventional gelatin system . this example is submitted to demonstrate this unexpected result . in this example , three ( 3 ) highly water soluble active ingredients were formulated into a fddf . these actives water solubilities are shown below : samples 1 , 3 and 5 ( the gelatin containing samples ) were prepared by adding the gelatin and mannitol to the vortex of the stirred , purified water . the mix was then heated to a temperature of 60 ° c . (± 1 ° c .) to place the gelatin and mannitol into solution . the solution was subsequently cooled to a temperature of 24 ° c . (± 1 ° c .) and the required amount of the active material was then added . each batch was held for a minimum of one ( 1 ) hour prior to dosing into the blister packs . samples 2 , 4 and 6 ( the modified starch samples ) were prepared by adding the starch and the mannitol to a clean , dry beaker and dry mixing the materials with a spatula . the purified water was subsequently added to this mix and homogenized using the silverson l4r homogenizer — small head adapter at half speed for a period of two ( 2 ) minutes . the recited active material was then added to this solution and left for a minimum of one ( 1 ) hour prior to dosing . no heating of these batches was required or undertaken . each sample was dosed to a 20 blister pack using a hamilton microlab , which delivered 500 mg of the mixture (± 2 %) into the aluminum blister pockets . the blister packs were then frozen at a temperature of − 110 ° c . using liquid nitrogen at a residence time of 3 . 2 minutes . the frozen samples were subsequently stored at − 25 ° c . prior to freeze drying . freeze drying was accomplished using a − 10 ° c . to 10 ° c . temperature cycle at 0 . 5 mbar . the samples were dried overnight on the same day as manufacture . after freeze drying , each pack was removed and inspected . each sample blister was inspected for cracking . this cracking is visually evident from an inspection of the fddf and it was determined that 90 % of sample 1 evidenced cracking while 0 % was evident for sample 2 ( the modified starch containing comparative ). sample 3 , containing the gelatin , evidenced a 45 - 50 % cracking rate whereas the starch - based formula , sample 4 , showed no cracking . sample 5 containing 2 . 5 weight % of phenylpropanolamine and 4 weight % gelatin evidenced a cracking rate of from 60 - 70 %. this means that 60 - 70 % of the 20 blister fills for this sample evidenced cracking and crumbled upon attempted removal from the blister pack . in contrast , the use of the starch in sample 6 evidenced only a 10 - 20 % cracking rate . this experiment readily demonstrates that the use of a modified starch in a fddf allows high levels of highly water soluble actives to be incorporated in the fddf without experiencing cracking and degradation of physical stability as seen with the conventional gelatin formulation . from the work conducted in example 7 , it is evident that the use of modified starch in a fddf allows for higher loading of the dosage form without the occurrence of cracking and / or physical failure . an effort was made to determine how much additional material would be required to prepare a gelatin based fddf containing the same amount of active ingredient , per dosage form . in essence , this experiment was conducted to determine if gelatin based formulas containing highly soluble actives can be prepared without meltback ( absorption of water vapor and degradation of physical stability ) and cracking problems . the following formulations were prepared : these samples were manufactured as set forth in example 7 except that a 750 ml fill was used . upon removal of the samples from the freeze drying , visual inspection resulted in none of the samples containing cracks . this example demonstrates that larger dosage units are required if gelatin is used in the preparation of the fast dissolving dosage forms . this unexpected result is advantageous in that the smaller dosage forms utilizing the modified starch will enhance patient compliance and reduce the cost of manufacture . this invention relates to fast dissolving dosage forms for oral administration . the advantages of fast dispersing dosage forms include the lingual , sublingual or buccal delivery of drugs . the current , most commercially popular form is a rapidly soluble solid dosage form that is made by aliquoting a slurry of therapeutic agent , solvent , gelatin and other excipients into preformed depressions . the liquid is then frozen and the solvent is then removed by sublimation , typically freeze drying . the resulting tablet has an open porous matrix that dissolves rapidly on contact with saliva . the use of the conventional fddf &# 39 ; s has certain drawbacks such as 1 ) the use of mammalian - derived gelatin ; 2 ) the limited loading of highly water soluble actives in the fddf ; 3 ) lack of mechanical strength ; 4 ) unpleasant taste ; 5 ) inability to provide homogeneity to the mix ; 6 ) inability to prevent sedimentation of active particles ; and 7 ) minimal cold water dissolution . the present invention advances the state of the art of fddf by discovering that certain modified starches can be used to prepare fddfs that have improved physical stability ; an unexpected ability to contain higher loadings of highly water soluble drugs ; improved taste ; improved physical stability ( resistance to moisture uptake and subsequent shrinkage when compared to gelatin matrix systems ); and a substantial reduction in the sedimentation rate of active particles in the mixture . it should be understood that the specification and examples are illustrative but not limitative of the present invention and that other embodiments within the spirit and scope of the invention will suggest themselves to those skilled in the art .
the present invention relates to fast dispersing solid dosage forms that preferably dissolve in the oral cavity within sixty , more preferably within thirty , most preferably within ten seconds . a novel feature of the solid dosage forms according to the invention reside in the fact that the composition is essentially free or absolutely free of mammalian gelatin . it has been discovered that the use of certain modified starches at concentrations from 20 to 90 % by weight of the solid dosage form prepares dosage forms that are mechanically and chemically stable and are able to deliver higher concentrations of an active ingredient than the heretofore utilized gelatin based fast dispersing solid dosage forms . further , the solid dosage forms according to the invention are obtainable by removing a solvent , such as water , from a mixture comprising an active ingredient , a modified starch and a matrix forming agent via freeze drying .