FORM 2
The Patents Act, 1970
(39 of 1970)
COMPLETE SPECIFICATION
[See, section 10]
" Palatable taste masked formulations of phosphodiesterase inhibitors and the process for preparation thereof
APPLICANT
Ajanta Pharma Limited
An Indian Company,
Registered under Companies Act, 1956
And having its Registered Office at:
Ajanta House, 98 Govt. Industrial Area,
Charkop, Kandivli (W), Mumbai - 400 067,
Maharashtra, India
INVENTORS
The inventors under Sec.28 are:
1. JATHAR, Shripad Rhushikesh ;
Working as Research Scientist at Research Centre,
Ajanta Pharma Limited, Ajanta House, Charkop, Kandivli (W),
Mumbai - 400 067, Maharashtra, India
Nationality: being Indian nationals.
The following specification describes the nature of the invention;

FIELD OF INVENTION.
The present invention describes formulation of phosphodiesterase inhibitors prepared by complexation with a complexing agent for taste masking of the bitter agent with resultant rapid effect for oral administration and process for preparation thereof. The active drug is type V phosphodiesterase inhibitor, sildenafil or a pharmaceutically acceptable salt thereof.
BACKGROUND OF INVENTION.
Sildenafil Citrate a pharmaceutically accepted salt of Sildenafil is designated chemically as 1 - [4 - ethoxy - 3 - (6, 7 - dihydro - 1 - methyl - 7 - oxo - 3 - propyl - l.H — pyrazolo [4, 3 - d] pyrimidine - 5 - yl] 4 -ethoxyphenyl] sulphonyl] - 4 - methyl piperazine citrate. It is a white to off-white crystalline powder with a solubility of 3.5 mg/ml in water and Mol wt. of 666.7. Sildenafil is the first orally administered drug for the treatment of male erectile dysfunction (MED) to be approved by US FDA.
Male erectile dysfunction (MED) can be defined as an inability to achieve penile erection or ejaculation. Its prevalence is claimed to be between 2% and 7% of the human male population, increasing with age up to 50 years and between 18% and 80% between 55 and 80 years of
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age. Typically, erectile dysfunction results from a combination of psychogenic and organic factors.
Psychotherapy is often engaged in alleviating psychogenic factors that limit the success of medical and surgical therapy, even in patients with MED of organic factors.
Many treatments are available for the MED of organic origin depending upon the cause and nature of problem like the vascular surgery, administration of vasodilator drugs or the likes.
MED treatment was revolutionized by the unexpected discovery of cGMP PDE inhibitor sildenafil citrate. It is useful in the treatment of erectile dysfunction and could be administered orally, which could obviate the disadvantages associated with other therapies.
The physiological mechanism of erection involves release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation, nitric oxide then activates the enzyme guanylate cyclase which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood.
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Sildenafil enhances the effect of nitric oxide (NO) by inhibiting phosphodiesterase type 5 (PDE 5) which is responsible for degradation of cGMP in the corpus cavernosum. When sexual stimulation causes local release of nitric oxide, inhibition of PDE5 by Sildenafil causes increased levels of cGMP in the corpus cavernosum, resulting in smooth muscle relaxation and inflow of blood to the corpus cavernosum (Physicians' Desk Reference, 53rd Edtn, Pub: Medical Economics Company, Inc., pg. 2424, 1999).
The drug is rapidly absorbed after oral administration and has an absolute bioavailability of 40 %. Maximum plasma concentrations are reached within 30 to 120 minutes and has an elimination half life of 4 hours.
The product containing sildenafil citrate was launched in the US after being approved by FDA in May 98. The product is available in the market in the name of Viagra from Pfizer USA. It is formulated as a blue film coated tablet containing equivalent to 20, 50 and 100 mg of sildenafil. The product has been widely used and has become the drug of choice to treat erectile dysfunction.
However the time required for conventional oral dosage forms to achieve desired effect is long with peak plasma levels between 30 to 120 minutes and would vary greatly, due to difference in absorption based

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on a wide variety of factors such as age of the patient, interval since, and size and composition of the last meal consumed by the patient. Conventionally, sildenafil should be administered orally about at least one hour before the intercourse. This would be a major shortcoming where a reliable, much rapid effect is highly desired for the optimum treatment. Further due to such delay patient may be tempted to take extra dose in want to achieve the desired action much rapid.
Therefore, in view of the aforementioned drawbacks associated with conventional sildenafil citrate dosage form for the treatment of male erectile dysfunction, it is apparent that there exists a need for formulations with rapid effect, and which are safe and convenient for oral administration.
The present investigation is therefore aimed at developing palatable formulations of this wonder drug sildenafil citrate with rapid onset of action and as a taste masked pleasantly flavoured and colored stable formulation, which may be in the form of tablets which when kept in mouth dissolves thereby giving faster dissolving formulation, as compared to conventional tablets. It may also be in the form of Jellyy Jelly cube or liquid to get the desired taste effect.
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PRIOR ART.
International patent application No. WO 9428902, equivalent to granted US patent no. 6469012 on 22.10.2002 to Ellis peter et al, describes pyrazolopyrimidinones for the treatment of impotence. The compound can be administered intravenously, sublingually or buccally. However the art fails to give the compositions and method of making such dosage forms.
Japanese patent application no. 10298062 discloses sildenafil citrate tablets rapidly soluble in the oral cavity and manufacture thereof. However the art dose not disclose the means adopted for taste masking of sildenafil citrate, which has extremely bitter taste leading to poor patient compliance.
International patent application no. WO9830209 relates to the rapidly releasing and taste-masking pharmaceutical dosage form in the form of fine granules, tablets, POS (powder for oral suspension), capsules or the like, comprising of core average particle diameter 80 -400 micrometer containing pharmaceutically active ingredient, low-substituted hydroxypropyl cellulose and Microcrystalline cellulose, inner coating layer formed on the core and containing a water-soluble polymer; and an outer coating layer formed on the inner coating layer and containing a saliva-insoluble polymer; further optionally coated by

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sugar coating. It is apparent that the compositions as well as the manufacturing process as disclosed are very complex involving large numbers of ingredients, prepared by process involving many steps requiring specialized equipment.
European patent application no. EP0960621 relates to the pharmaceutical formulations of the compound sildenafil in particular rapidly disintegrating oral dosage forms, which contain sildenafil in the form of its free base. The pharmaceutical formulations make use of sildenafil in the form of free base having extremely low solubility in water and saliva. As states therein such formulations with sildenafil free base can provide a blood plasma levels of active ingredient which are virtually identical to those achieved with conventional tablet or capsule formulations of sildenafil citrate. Thus the art indicates only the possibility of the achieving desired effect but does not demonstrate it.
International patent application no. WO0054777 describes a controlled release composition containing sildenafil for delivery via the sublingual or buccal routes. Compositions of this particular art are controlled release type and include special ingredients such as osmotic agent, water dispersible polymer or the like for the said purpose. Also as stated therein the controlled release composition releases drugs relatively slowly over an extended time period. Moreover the use of osmotic agent like mannitol in an amount as much as 47 percentage per
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tablet weight, would tend to make tablets hygroscopic in nature, which could affect the stability of the product adversely.
International patent application no. WO0205820 discloses solid dispersions of sildenafil citrate with certain highly water soluble sugars. The method of making involve mixing sildenafil citrate with highly water soluble sugar, heating the mixture to at least 190°C, rapidly cooling to form glassy solid, size reduction and incorporating into dosage form. It is known in the art that heating of an active drug to such a high temperature could cause degradation of the active drug, which could adversely affect the efficacy of the product thereby making it ineffective. Also the stability of the product after such heating of active at a very high temperature followed by rapid cooling has not been illustrated.
United States published patent application no. 20020004498 and granted patent no. 6403597, discloses transmucosal administration of phosphodiesterase inhibitors for the treatment of erectile dysfunction. Preferred modes of administration include transbuccal, sublingual and transrectal routes. The preparation however involves use of glycerin as high as 30% per dosage unit weight by weight. Moreover the product is prepared by molding methods. Thus the tablets containing such high percentage of glycerin, which is known to be, very hygroscopic and prepared by direct molding would make the tablets very friable, and would not meet the hardness required for withstanding the breakage
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during commercial handling. Moreover the stability can also get affected adversely owing to the presence of high percentage of hygroscopic glycerin.
United States published patent application no. 20020071864 discloses a rapidly disintegrable tablet for oral administration, which disintegrates in the oral cavity within 60 seconds, consisting of therapeutically effective amount of an active ingredient, spray-dried mannitol, crospovidone and one or more pharmaceutically acceptable excipients. The disintegrable oral tablets include very high percentage of mannitol as high as 95 percentage weight by weight. Such a high amount of mannitol can pose the difficulty during processing and can have detrimental effect on the tablet characteristic and stability. Mannitol has a tendency to make the formulation hygroscopic which could affect its hardness. It is known in the art that the tablets which are of not of requisite hardness would tend to break easily during packaging, transportation, and storage.
Therefore, in view of the aforementioned deficiencies attended with prior art preparations it is obvious that there still exists a need for improved formulations of sildenafil citrate which are safe, reliable, convenient for oral administration, stable and with rapid effect and taste masked.

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OBJECTS OF THE INVENTION.
Accordingly, a major object of the present invention is to provide safe, taste masked and stable pharmaceutical formulations of sildenafil citrate with rapid effect, which can be very conveniently administered in the patients with Male Erectile Dysfunction (MED).
It is an object of the present invention to provide formulations of sildenafil citrate with rapid effect by way of specially designed oral dosage forms.
It is an object of the present invention to provide formulations of sildenafil citrate with rapid effect for oral administration in the form of soft tablet and mouth dissolving tablets.
It is an object of the present invention to provide formulations of sildenafil citrate with rapid effect for oral administration in the form of jelly and jelly cubes.
It is an object of the present invention to provide formulations of sildenafil citrate with rapid effect for oral administration in the form of liquid.
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It is an object of the present invention to provide formulation of Sildenafil Citrate by complexing with a complexing agent to achieve taste masking of the bitter drug.
It is an object of the present invention to provide formulation of Sildenafil Citrate prepared by complexation and suitably flavoured and colored to improve the taste and patient compliance.
It is an object of the present invention to provide process for preparation of safe, reliable and stable pharmaceutical formulations of sildenafil citrate with rapid effect, which can be very conveniently administered in the patient in need of treatment of male erectile dysfunction.
It is an object of the present invention to provide process for preparation of formulations of sildenafil citrate with rapid effect by way of specially designed oral dosage forms.
It is an object of the present invention to provide process for preparation of formulations of sildenafil citrate with rapid effect for oral administration in the form of soft tablet and mouth dissolving tablets.
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It is an object of the present invention to provide process for preparation of formulations of sildenafil citrate with rapid effect for oral administration in the form of jelly and jelly cubes.
It is an object of the present invention to provide process for preparation of formulations of sildenafil citrate with rapid effect for oral administration in the form of liquid.
It is an object of the present invention to provide a process for formulation of Sildenafil Citrate by complexing with a complexing agent to achieve taste masking of the bitter drug.
It is an object of the present invention to provide a process formulation of Sildenafil Citrate prepared by complexation and suitably flavored and coloured to improve the taste and patient compliance.
Thus the present invention is aimed at providing formulations of wonder drug sildenafil citrate with rapid effect. Further, from the following detailed description it will be apparent that other various features, aspects and advantages of the present invention remains absent from the prior arts.
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SUMMARY OF INVENTION
The present invention- discloses the palatable formulations of phosphodiesterase inhibitors, administered in the patient in need of treatment Male Erectile Dysfunction (MED)., prepared by complexation with a complexing agent for taste masking of the bitter agent with rapid effect and process for preparation thereof. The active drug is type V phosphodiesterase inhibitor, sildenafil or a pharmaceutically acceptable salt, more specifically sildenafil citrate or the like. The complexed finished dosage form could be in the form of tablets , soft tablets, jelly, jelly cubes and liquids or the like thereof.
DETAILED DESCRIPTION OF THE INVENTION.
Sildenafil a potent and selective inhibitor of type 5 cGMP (cyclic guanosine monophosphate phosphoesterase with utility for the treatment of male erectile dysfunction (Terett, N, K; et al. sildenafil (Viagra), a potent and selective inhibitor of type 5 cGMP phosphoesterase with utility for the treatment of male erectile dysfunction, Biorg. Med. Chem. Lett. 6(5), 1819-1824) 1996).
The present invention is directed towards development of specialized formulation of sildenafil citrate with rapid effect for oral administration.

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The present invention is directed towards development of specialized formulation of sildenafil citrate with taste masked for oral administration.
Oral administration is probably the most prevalent method of administering pharmacological medicaments. The drug is generally incorporated into a tablet, capsule, and then swallowed. The oral route of administration is often preferred because of its convenience.
Nevertheless, oral administration of dosage forms to be swallowed suffers from several disadvantages in those patients especially in geriatric population who have difficulty in swallowing, and such patients would definitely prefer the other oral dosage forms, which do not require to be swallowed. In addition, the act of swallowing the medicament often require fluids, resulting in increased gastric volume and the likelihood of nausea and vomiting.
A further problem with oral administration of conventionally available sildenafil citrate formulation is that the rate of absorption of the drug into the bloodstream after swallowing varies from patient to patient. The absorption of the drug is dependent upon the movement of the drug from the stomach to the small and large intestines, on the effects of secretions from these organs, and on the resulting pH within

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the stomach and intestines. Moreover anxiety and stress can dramatically reduce these movements and secretions, prevent or reduce the final effects of the drug, and delay onset of the drug effect.
Most significant is the fact that there is normally a substantial delay between the time of oral administration and the time that the therapeutic effect of the drug begins. As mentioned above, the drug must pass through the gastrointestinal system in order to enter the bloodstream; this typically takes forty-five minutes or longer. Further stress can often increase this delay. Therefore conventional sildenafil citrate formulations are required to be administered at least 1 to 3 hours before the intercourse.
Therefore the present invention provides formulations of sildenafil citrate with rapid effect by way of specially designed oral dosage forms with easy absorption and rapid delivery of the drug to the blood stream after administration. Furthermore the present invention oral dosage forms of sildenafil citrate are so formulated to have simplicity and economy in manufacturing, convenience in portability and dispensing and with good shelf life.
Accordingly the present invention provides formulations of sildenafil citrate with rapid effect which can offer significant advantages
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where immediate effectiveness of the drug is required over the conventionally available formulations.
The formulations of sildenafil citrate with rapid effect in accordance with the present invention comprise a therapeutically effective amount of the sildenafil citrate and pharmaceutically acceptable safe inert excipients.
The formulations of sildenafil citrate with rapid effect in specially designed oral dosage forms as provided herein includes a unit dosage of sildenafil citrate, the unit dosage being therapeutically effective dosage required for treatment of male erectile dysfunction like 25 mg, 50 mg and 100 mg as sildenafil citrate equivalent to base.
The pharmaceutically acceptable safe inert excipients and adjuvants which may be used in the formulations for the manufacturing of tablets or soft tablets include, but are not limited to, diluents, disintegrating agents, solubility enhancer, lubricant, wetting agents, glidant, and for manufacturing of jelly , jelly cubes and liquids include solubility enhancer, viscosity enhancer, a pH adjusting substance, taste, masking agents, colours, flavours, sweeteners, preservatives and the like. Additional components that may be incorporated into sublingual dosage forms are known, or will be apparent., to those skilled in this art;
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for example, see Remington: The Science and Practice of Pharmacy, 19th edition (Mack Publishing, 1995).
The present invention comprises of preparing the drug - mask complex using a complexing agent belonging to the category of cation exchange resin based on crosslinked polyacrylic acid matrix or sulphonated co-polymer of styrene and divinyl benzene, or crosslinked polymethacrylic acid. The complexing agent can also be used belonging to the category of anionic exchange. The complex is prepared by a reaction of drug with the complexing agent for definite time interval in water as the medium and the complex is separated from the medium by centrifugation and drying. The dried complex is then used in the preparation of the tablets in the conventional manner.
The specially designed pharmaceutical formulations of sildenafil citrate with rapid effect under the description of the present invention are in the form of oral dosage forms. The oral dosage forms can be in the forms like soft tablets, mouth dissolving tablets, fine granules, powder for oral suspension, powders to be filled in sachet, jelly, jelly cubes, liquid or the like.
The present invention also provides a process for preparing various dosage forms.
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EXAMPLE 1:
Taste masked Soft Tablet Formulation
FORMULA FOR BATCH SIZE OF 1.0 LAC TABLETS

SR. NO. INGREDIENTS LABELCLAIMPER TAB THEORETICAL QTY. In Kg
1 Sildenafil Citrate 100 mg 14.04
2 Complexing agent 42.14
3 Citric acid BP 0.75
4 Sodium chloride 0.75
5 Mannitol Instant BP 9.345
6 Aspartame 1.5
7 Monoammonium Glycerrihyzinate 0.75
8 Croscarmellose sodium USP 3.0
9 Menthol 0.025
10 Magnesium stearate BP 1.5
11 Peppermint Flavour 0.75
12 Colour: Brilliant Blue FCF 0.03
13 Colour: Lake Brilliant Blue 0.42
The procedure consists of preparing the drug and the mask complex. The complexation is prepared by dissolving drug in 425 L of water and stirring for 30 minutes. This is followed by addition of the Complexing
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agent slowly under stirring and to continue stirring for 4 hours. The filtrate is analyzed for uncomplexed drug.
The complexed resulting suspension is then fed to a super centrifuge and the suspension is filtered to separate the complex from the filtrate. The complex is obtained as a semi dried mass and is further dried in a fluid bed drier till the dry powder of desired LOD is achieved.
The complex is then mixed with the excipients such as citric acid sodium chloride, flavour colour etc. The blend is lubricated with Magnesium stearate and compressed into soft tablets with mint flavour.
EXAMPLE 2:
Taste masked Oral Jelly
FORMULA FOR BATCH SIZE OF 100.0 Kg

SR. NO. INGREDIENTS LABEL CLAIM PER 5g ASSIGNEDQUANTITYIn Kg.
1. Sildenafil Citrate equivalent to Sildenafil 50 mg 0.720
2. Sucrose IP (Pulverized) 39.600
3. Methylparaben Sodium IP 0.180
4. Propylparaben Sodium IP 0.020
5. Sodium saccharine IP 0.500
6. Sodium chloride IP 0.250
7. Propylene glycol IP 10.000
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8. Sorbitol solution 70 % IP 10.000
9. Sodium CMC IP 1.000
10. Citric acid IP 0.250
11. Color : brilliant blue FCF 0.005
12. Peppermint flavour oil RSPP 0.100
13. Menthol IP 0.010
14. D. I. Water 36.680
Procedure: The process is initiated by preparing the syrup by dissolving the required quantity of sugar in water, followed by addition of methylparaben and propyl paraben as preservatives. To this is added sodium CMC and allowed to soak overnight. The syrup so produced is then passed through Colloid mill to ensure breaking of lumps and smooth mouth feel.
The drug is dispersed in Propylene glycol and the resultant is added to the syrup solution prepared under stirring. The other ingredients are added such as the sorbitol, flavour and colour and the volume is made up using water. The jelly formed is finally passed through colloid mill once again for homogenous distribution of drug in the base.
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EXAMPLE 3:
Taste masked Oral liquid formulation
FORMULA FOR BATCH SIZE OF 1.0 Ltr

SR. NO. INGREDIENTS LABELCLAIMPER 5ml ASSIGNEDQUANTITYIng
1 Sildenafil Citrate 50 mg 14.61
2 Sucrose IP (pharma grade) 300.0
3 Methylparaben 1.8
4 Propylparaben 0.2
5 Propylene glycol IP 500 ml
6 Saccharin sodium IP 2.5
7 Sodium chloride IP 2.5
8 Brillant Blue FCF 0.02
9 Menthol IP 0.1
10 Peppermint oil RSPP (Bush Boake Allen (I) Ltd.) 1.0 ml
11 Water q.s. 1000 ml
Procedure: The process is initiated by preparing the sugar syrup by dissolving the required quantity of sucrose in water and boiling. To this are added methyl and propyl parabens as preservatives. And the solution is allowed to cool.
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In a separate vessel propylene glycol is warmed to a temperature of 75-80°C and to this is added drug incrementally till the required quantity is completed. It is to be ensured that the drug is completely dissolved and the resulting solution is clear.
The drug solution is cooled and then added to the previously prepared syrup solution. This mix is then topped up with the required colour, flavour and the volume is made up with water.
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WE CLAIM
1. A method for preparation of Palatable formulations of phosphodiesterase inhibitors with rapid effect, which are in the form of soft tablets or jelly or jelly cubes or liquids and contains the active agent Sildenafil citrate or its pharmaceutically acceptable salts. The, active ingredient is taste masked by complexation to enhance the palatability of the formulation.
2. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 1, wherein the active agent is a Type V phosphodiesterase inhibitor, selected from the group consisting of sildenafil, tadalafil, vardenafil and the like.
3. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 1, wherein the Type V phosphodiesterase inhibitor is sildenafil or a pharmaceutically acceptable salt thereof, more preferably sildenafil citrate or the like.
4. Palatable taste masked formulations of phosphodiesterase inhibitors
with rapid effect according to claim 1, wherein the formulation is a fast release dosage form.

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5. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 4, wherein the formulation is prepared by complexing with a complexing agent to achieve taste masking of the bitter active drug.
6. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 5, wherein the masking agent used to mask the bitter taste is a cationic or anionic exchange resin such as Polacrillin potassium and the like.
7. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 4, wherein the fast release dosage form provides drug release in the oral cavity within 5 minutes.
8. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 4, wherein the pharmaceutical formulation is selected from the group consisting of soft tablet and mouth dissolving tablets, jelly and jelly cubes, liquids, solutions, suspensions syrups granules, beads, powders and pellets.
9. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 8, wherein the pharmaceutical formulation comprises a soft tablet and mouth dissolving tablets.
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10. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 9, wherein the pharmaceutical formulation contains the drug sildenafil in the dose of 25, 50 or 10.0 mg added as sildenafil citrate.
11. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 8, wherein the pharmaceutical formulation comprises a jelly and jelly cubes.
12. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 11, wherein the pharmaceutical formulation is in the form of an oral. Jelly or jelly cubes and is dispensed as a unit dose per 5 grams. The drug content per 5 grams is 25, 50, or 100 mg of Sildenafil added as sildenafil citrate.
13. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 8, wherein the pharmaceutical formulation comprises a liquid.
14. Palatable taste masked formulations of phosphodiesterase inhibitors
with rapid effect according to claim 13, wherein the pharmaceutical formulation is in the form of liquid and is dispensed as a unit dose per 5 ml. The drug content per 5 ml is 25, 50, or 100 mg of Sildenafil added as sildenafil citrate.
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15. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 1, wherein the active agent is a Type V phosphodiesterase inhibitor, selected from the group consisting of sildenafil, tadalafil, vardanefil and the like.
16. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 15, wherein the Type V phosphodiesterase inhibitor is sildenafil or a pharmaceutically acceptable salt thereof, more preferably sildenafil citrate or the like.
17. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 16, wherein the formulation is a fast release dosage form.
18. A process for preparation of palatable taste masked formulations of
t,
phosphodiesterase inhibitors with rapid effect according to claim 17, wherein the formulation prepared by complexing with a complexing agent to achieve taste masking of the bitter active drug.
19. A process for preparation of palatable taste masked formulations of
phosphodiesterase inhibitors with rapid effect according to claim 18,
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wherein the masking agent used to mask the bitter taste is a cationic or anionic exchange resin such as Polacrillin potassium and the like:
20. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 17, wherein the fast release dosage form provides drug release in the oral cavity within 5 minutes.
21. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 17, wherein the pharmaceutical formulation is selected from the group consisting of soft tablet and mouth dissolving tablets, jelly and jelly cubes, liquids, solutions, suspensions syrups granules, beads, powders and pellets.
22. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 21, wherein the pharmaceutical formulation comprises a soft tablet and mouth dissolving tablets.
23. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 22, wherein the pharmaceutical formulation contains the drug sildenafil in the dose of 25, 50 or 100 mg added as sildenafil citrate.
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24. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 21, wherein the pharmaceutical formulation comprises a jelly and jelly cubes.
25. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 24, wherein the pharmaceutical formulation is in the form of an oral Jelly or jelly cubes and is dispensed as a unit dose per 5 grams. The drug content per 5 grams is 25, 50, or 100 mg of Sildenafil added as sildenafil citrate.
26. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 21, wherein the pharmaceutical formulation comprises a liquid.
27. A process for preparation of palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 26, wherein the pharmaceutical formulation is in the form of liquid and is dispensed as a unit dose per 5 ml. The drug content per 5 ml is 25, 50, or 100 mg of Sildenafil added as sildenafil citrate.
28. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect according to claim 1, wherein formulations can be

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very conveniently administered in the patient in need of treatment Male Erectile Dysfunction (MED).
29. Palatable taste masked formulations of phosphodiesterase inhibitors with rapid effect thereof substantially as herein described with reference to each of the examples.


The Controller of Patents,
The Patent Office Branch, at Mumbai - 400 013

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ABSTRACT
The present invention describes formulation of phosphodiesterase inhibitors type V, administered in the patient in need of treatment Male Erectile Dysfunction (MED), prepared by complexation with a complexing agent for taste masking of the bitter agent with rapid effect for oral administration and process for preparation thereof. The active drug is type V phosphodiesterase inhibitor, sildenafil or a pharmaceutically acceptable salt, more specifically sildenafil citrate or the like. The complexed finished dosage form could be in the form of tablets , soft tablets, jelly, jelly cubes and liquids or the like thereof.
5 JUL 2004
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