FIELD OF INVENTION

The present invention relates to the pharmaceutical composition comprising Levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and the process for preparing the same.

BACK GROUND OF THE INVENTION

Levodopa, an aromatic amino acid, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 197.2. It is designated chemically as (-)-L-a-amino-β (3,4-dihydroxybenzene) propanoic acid. Its empirical formula is C9H11NO4, and its structural formula is

Carbidopa, an inhibitor of aromatic amino acid decarboxylation, is a white, crystalline compound, slightly soluble in water, with a molecular weight of 244.3. It is designated chemically as (-)-L-(a-hydrazino-(a-methyl-P-(3,4-dihydroxybenzene) propanoic acid monohydrate. Its empirical formula is C10Hl4N2O4XH2O, and its structural formula is


Levodopa and carbidopa are most commonly used drugs in the treatment of the Parkinson's disease. Levodopa and carbidopa are commercially available as a combination with the trade name SINMET in the dosage form of tablets and marketed by Merck Sharp & Dohme limited in UK.

Entacapone, an inhibitor of catechol-O-methyltransferase (COMT), is a nitro-catechol-structured compound with a molecular weight of 305.3. The chemical name of entacapone is (E)-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)-N,N-diethyl-2-propenamide. Its empirical formula is C14H15N3O5 and its structural formula is

Entacapone is described in the European patent EP0444899 Bl as a Catechol-O-methyl- transferase (COMT) inhibitor. The publication further discloses that for the treatment of the Parkinson's disease, entacapone is given with levodopa, in each of its own composition or combined in one composition. The European patent EPl 112065 B1 describes an oral compacted composition comprising a pharmaceutically effective amount of entacapone or a pharmaceutically acceptable salt thereof and a croslinked cellulose derivative. Entacapone is commercially available with the trade name COMTESS in the dosage form of film coated tablets and marketed by Orion Corporation in UK.

In the treatment regimen of Parkinsonism, medicament needs to be taken several times a day to the keep the patient without symptoms. In the regimen where two separate tablets i.e. one containing levodopa and carbidopa, and the other containing entacapone, is problematic for many patients, such as those with tremor and old age. The patient compliance has been improved by combining these three active ingredients i.e. levodopa, carbidopa and entacapone. Entacapone in combination with carbidopa and levodopa is commercially available with the trade name STALEVO in the dosage form of film coated tablets and marketed by Orion Corporation in UK.

European Patent EP1189608 Bl discloses an oral solid pharmaceutical composition comprising levodopa, carbidopa and entacapone or their pharmaceutically acceptable salts or hydrates thereof wherein the substantial portion of the carbidopa or pharmaceutically acceptable salt or hydrates thereof is separated from entacapone and levodopa or pharmaceutically acceptable salts or hydrates thereof in the tablet. The applicants of this patent further states that it is very difficult to adjust the absorption of the three different active agents from one and the same oral solid composition. It states that the applicants have found a particular interesting way to increase the bioavailability of carbidopa from an oral solid composition comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is to add carbidopa separately for instance by granulating first levodopa and entacapone together and then adding carbidopa to these granules separately.

WO2008053297 A2 describes the single oral composition comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts thereof, where in substantial portion of entacapone or a pharmaceutically acceptable salt or hydrate thereof is separated from the mixture of levodopa and carbidopa or pharmaceutically acceptable salts or hydrates thereof

The present formulation poses a challenge to the formulator to formulate the dosage form comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof as the three active ingredients are highly desirable to be released from the oral solid composition in a manner so as to achieve the targeted ranges of the pharmacokinetic parameters which in turn would ensure optimal therapeutic activity. It is very challenging to achieve the absorption of the three active ingredients to the therapeutic concentration. It is essential to achieve the desired dissolution profile in different pH media to get the desired absorption. So there is a need to develop a stable solid pharmaceutical composition comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates in order to achieve the desired release of the three active ingredients.

SUMMARY OF THE INVENTION

The present invention relates to pharmaceutical composition comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and process for preparing the same.

The Present invention relates to the pharmaceutical composition comprising two discrete portions of the mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof

In further embodiment the invention relates to a pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the first discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the granules and the second discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the powder.

In further embodiment the invention relates to a pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the first discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the granules and the second discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the granules.

In further embodiment the invention provides a pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the ratio of mixtures levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof in the first discrete portion to the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof present in the second discrete portion is in the rangeof0.0l:1 to 1:0.01.

The present invention relates to a process for the preparation of the pharmaceutical composition comprising two discrete portions of mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the said process comprises a) wet granulating the first discrete portion of mixture comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof with atleast one pharmaceutically excipients with a binder solution to form granules, b) drying and optionally milling said granules, c) mixing said granules with the second discrete portion of the mixture comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and atleast one pharmaceutically excipients to form a blend, d) lubricating said blend with atleast one lubricant to form a final blend e) Compressing said final blend to form a tablet f) and if desired coating the tablet obtained in step e.

The present invention further relates to a process of the pharmaceutical composition comprising two discrete portions of mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the said process comprises a) wet granulating the first discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutical salts thereof or hydrates thereof with atleast one pharmaceutically acceptable excipient with a binder solution to form granules, b) wet granulating the second discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof with atleast one pharmaceutically acceptable excipient with a binder solution to form the granules, c) mixing the granules of the first discrete portion granules and second discrete portion granules of step no a and b, d) lubricating the above mixture with the mixture, e) compressing the said lubricated blend to form the tablet and f) if desired coating the tablet obtained in step e.

DETAILED DESCRIPTION

The present invention relates to pharmaceutical composition comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and process for preparing the same.

The term "discrete portion" refers to a quantity of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof being separated from the other mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof

The present invention relates to the pharmaceutical composition comprising two discrete portions of the mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof.

In further embodiment the invention relates to a pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the first discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the granules and the second discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the powder.

In further embodiment the invention relates to a pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the first discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the granules and the second discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of the granules.

In further embodiment the invention provides a pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the ratio of mixtures levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof in the first discrete portion to the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof present in the second discrete portion is in the range of 0.01:1 to 1:0.01.

The stabilizer useful in the pharmaceutical composition of the present invention is acidic substance or alkaline substance or mixtures thereof.

The acidic substances used as the stabilizers in the stable pharmaceutical composition comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is selected from the group consisting of citric acid, tartaric acid, malic acid and mixtures thereof Out of these citric acid is most preferred acidic substance used as a stabilizer.

The alkaline substances used as the stabilizers the stable pharmaceutical composition comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is selected from the group consisting of sodium carbonate, ammonium carbonate, anhydrous sodium carbonate, sodium carbonate monohydrate, sodium tartrate, sodium potassium tartrate, sodium citrate, sodium hydroxide, calcium acetate, sodium acetate, dibasic sodium phosphate, anhydrous dibasic sodium phosphate, di ammonium hydrogen phosphate, sodium pyrophosphate and mixtures thereof Out of these alkaline substances di basic sodium phosphate, sodium citrate, ammonium carbonate and the mixtures thereof are most preferred alkaline substances used as a stabilizer.

The pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof preferably contains the stabilizer from 0.5% to 10% by weight of the total solid dosage form. Most preferably, the composition contains the stabilizer from 1 to 5% by weight of the total solid dosage form (e.g. 1 to 5% of the total tablet weight).

The stabilizer is present in the first discrete portion of the pharmaceutical composition of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof

Suitable fillers may include one or more of the microcrystalline cellulose and dibasic calcium phosphate. The filler used in the stable pharmaceutical composition of levodopa, carbidopa, and entacapone or pharmaceutically acceptable salts or hydrates thereof is microcrystalline cellulose. The microcrystalline cellulose is present in the range from about 5% to 50% w/w of the total pharmaceutical composition. Most preferably the microcrystalline cellulose may be present in the range from about 10% to 30% w/w of the total pharmaceutical composition. Microcrystalline cellulose is present both in the first and second discrete portion preferably in the range in the range of 4: 1 and more preferably in the range of 3:1.

Suitable binders may include one or more of povidone, starch, stearic acid, gums, hydroxy propyl methyl cellulose and the like.

Suitable lubricants may include one or more of magnesium stearate, zinc stearate, calcium stearate, stearic acid, sodium stearyl fumarate, hydrogenated vegetable oil and the like.

Suitable disintegrants may include one or more of crospovidone, sodium starch glycolate and Amberlite IRP-88.

The present invention relates to a process for the preparation of the pharmaceutical composition comprising two discrete portions of mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the said process comprises a) wet granulating the first discrete portion of mixture comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof with atleast one pharmaceutically excipients with a binder solution to form granules, b) drying and optionally milling said granules, c) mixing said granules with the second discrete portion of the mixture comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and atleast one pharmaceutically excipients to form a blend, d) lubricating said blend with atleast one lubricant to form a final blend e) Compressing said final blend to form a tablet f) and if desired coating the tablet obtained in step e.

The present invention further relates to a process of the pharmaceutical composition comprising two discrete portions of mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the said process comprises a) wet granulating the first discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutical salts thereof or hydrates thereof with atleast one pharmaceutically acceptable excipient with a binder solution to form granules, b) wet granulating the second discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof with atleast one pharmaceutically acceptable excipient with a binder solution to form the granules, c) mixing the granules of the first discrete portion granules and second discrete portion granules of step no a and b, d) lubricating the above mixture with the mixture, e) compressing the said lubricated blend to form the tablet and f) if desired coating the tablet obtained in step e.

The present invention is further illustrated by the following examples which are provided merely to be exemplary of the invention and don't limit the scope of the invention. Certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention.

Example-1

Table-1 provides the composition of the tablet comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof where all the active ingredients are wet granulated at the same time and compacted into the tablets

Table-1

Procedure: Levodopa, carbidopa monohydrate, entacapone, crospovidone, microcrystalline cellulose, Aerosil and citric acid are mixed in the double cone blender. The above blended material is wet granulated with the binder solution

comprising the hydroxypropyl methyl cellulose in the dichloromethane and isopropyl alcohol in the rapid mixture granulator. The above granules are dried in the tray dryer and milled through the sieve no #40. The above milled granules are lubricated with the magnesium stearate in the double cone blender. The lubricated blend is compressed into tablets and further film coated with the film coating solution.

Example-2

Table-2 provides the composition of the present invention

Table-2

Procedure: The pharmaceutical composition is prepared by mixing the first discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone with the microcrystalline cellulose, citric acid, aerosil in a double cone blender. The blended mixture is wet granulated with the binder solution comprising the hydroxypropyl methyl cellulose in isopropyl alchol and dichloro methane in the rapid mixture granulator. The granules are dried in the tray dryer and milled through the sieve #40. The granules prepared are mixed with the second discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone, microcrystalline cellulose, crospovidone in a double cone blender and lubricated with magnesium stearate. The lubricated blend is compressed into the tablets and further film coated with the film coating solution.

Example-3

Table-3 provides the composition of the present invention

Table-3

Procedure: The pharmaceutical composition is prepared by mixing the first discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone with the microcrystalline cellulose, citric acid, aerosil in a double cone blender. The blended mixture is wet granulated with the binder solution comprising the hydroxypropyl methyl cellulose in purified water in the rapid mixture granulator. The granules are dried in the tray dryer and milled through the sieve #40. The granules prepared are mixed with the second discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone, microcrystalline cellulose, crospovidone in a double cone blender and lubricated with magnesium stearate. The lubricated blend is compressed into the tablets and further film coated with the film coating solution.

Example-4

Table-4 provides the composition of the present invention

Procedure: The pharmaceutical composition is prepared by mixing the first discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone with the microcrystalline cellulose, citric acid, aerosil in a double cone blender. The blended mixture is wet granulated with the binder solution comprising the hydroxypropyl methyl cellulose in isopropyl alchol and dichloro methane in the rapid mixture granulator to form the granules of the first discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone. The granules of the first discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone are dried in the tray dryer and milled through the sieve #40. The second discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone with the microcrystalline cellulose and crospovidone is wet granulated with the binder solution comprising the hydroxy propyl methyl cellulose in isopropyl alchol and dichloro methane in the rapid mixture granulator to form the granules of the second discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone. The granules of the second discrete portion of the mixture levodopa, carbidopa monohydrate and levodopa are dried in the tray dryer and milled through sieve #60. The granules comprising the first discrete portion of the mixture of levodopa, carbidopa monohydrate and entacapone and the granules comprising the second discrete portion of the mixture of the mixture of levodopa, carbidopa monohydrate and entacapone are mixed in the double cone blender and lubricated with the magnesium stearate to form the lubricated blend. The above lubricated blend is compressed into the tablets and further film coated with the film coating solution.

Example-5:

The Invitro release profile of the example-1 in comparison with the example-2 was obtained with the following parameters.

Media: 0.1N Hcl, pH 5.5 phosphate buffer
Volume: 750ml for 0.1N Hcl, 900 ml for pH 5.5 phosphate buffer
Apparatus: USP I (Basket)
Speed: 50 rpm for O.IN Hcl, 125 rpm for pH 5.5 Phosphate buffer

Table-5

LD: Levodopa CD: Carbidopa ENT: Entacapone
The results demonstrate that the release of the three active ingredients from the formulation is more in the example-2 compared with the example-1.

We claim

1. A pharmaceutical composition comprising two discrete portions of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof

2. A pharmaceutical composition of claim1 wherein the first discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of granules and the second discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of powder

3. A pharmaceutical composition of claim1 wherein the first discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of granules and the second discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the form of granules.

4. A pharmaceutical composition of claim 1 wherein the ratio of first discrete portion mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and the second discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the range of 0.01:1 to 1:0.01.

5. A process for the preparation of the pharmaceutical composition comprising two discrete portions of mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the said process comprises a) wet granulating the first discrete portion of mixture comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof with atleast one pharmaceutically excipients with a binder solution to form granules, b) drying and optionally milling said granules, c) mixing said granules with the second discrete portion of the mixture comprising levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and atleast one pharmaceutically excipients to form a blend, d) lubricating said blend with atleast one lubricant to form a final blend e) Compressing said final blend to form a tablet f) and if desired coating the tablet obtained in step e.

6. A process for preparation of the pharmaceutical composition of claim 5 wherein the ratio of first discrete portion mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and the second discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the range of 0.01:1 to 1:0.01.

7. A process for the pharmaceutical composition comprising two discrete portions of mixtures of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof wherein the said process comprises a) wet granulating the first discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutical salts thereof or hydrates thereof with atleast one pharmaceutically acceptable excipient with a binder solution to form granules, b) wet granulating the second discrete portion of the mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof with atleast one pharmaceutically acceptable excipient with a binder
solution to form the granules, c) mixing the granules of the first discrete portion granules and second discrete portion granules of step no a and b, d) lubricating the above mixture with the mixture, e) compressing the said lubricated blend to form the tablet and f) if desired coating the tablet obtained in step e.

8. A process for preparation of the pharmaceutical composition of claim 7 wherein the ratio of first discrete portion mixture of levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof and the second discrete portion of the mixture of the levodopa, carbidopa and entacapone or pharmaceutically acceptable salts or hydrates thereof is in the range of 0.01:1 to 1:0.01.