Indian Patents. 226948:PROCESS FOR PREPARING ALMODIPINE MESYLATE MONOHYDRATE

Title of Invention	PROCESS FOR PREPARING ALMODIPINE MESYLATE MONOHYDRATE
Abstract	Amlodipine mesylate monohydrate is prepared either from anhydrous amlodipine mesylate, or in the presence of a water immiscible solvent medium from amlodipine free base and methane sulphonic acid.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See section 10, rule 13) “PROCESS FOR PREPARING ALMODIPINE MESYLATE MONOHYDRATE” CIPLA LIMITED of 289 Bellasis Road, Mumbai Central, Mumbai 400 008, India. The following specification particularly describes the invention and the manner in which it is to be performed. WO 2004/096770 PCT/GB2004/001638 -2- PROCESS FOR PREPARING ALMODIPINS MESYLATE MONOHXDRATE The present invention is concerned with a process for preparing amlodipine mesylate monohydrate. Amlodipine is the international non-proprietary name of 2-f(2-Aminoethoxy)- methyl]-4-(2-chlorophenyl),4-dihydro-6-methyl-3,5-pyridinecarboxilic acid 3-ethyl 5- methyl ester. Amlodipine is known to be a calcium channel blocker and has therapeutic applications in the treatment or prevention of a number of cardiac conditions, such as angina pectoris, cardiac antihypertensive, heart attacks, cardiac hypertrophy and related cardiac conditions, and also as an antihypertensive agent, for example in the treatment of coronary vasospasm. Amlodipine is the title compound of Example 9 of European Patent 008P167B and its preparation is described therein, European Patent 0089167B describes suitable pharmaceutically acceptable salts of the compounds described therein, including the hydrochloride, hydrobromide, sulphate, phosphate or acid phosphate, acetate, maleate, fumarate, lactate, tartrate, citrate and gluconate salts. Maleate is described as the preferred salt The preparation of the maleate salt of amlodipine is described in Examples 11 and 12 of European Patent 0089167B. European Patent Application 0244944A describes further salts of amlodipine, and describes the besylate salt of amlodipine as being a particularly preferred salt US Patent 6057344 describes the use of (-)amlodipine, substantially tree of its (+) stereoisomer, in eliciting an antihypertensive effect and also for use in the treatment of angina. Preferred pharmaceutically acceptable salts described in US Patent 6057344 are derived from besylate, hydrobromic, hydrochloric, phosphoric and sulphuric acids. US Patent Application 2002/0045648 describes a pharmaceutical composition comprising an NO-releasing amount of the R(+)enantiomer of amlodipine or of a pharmaceutically acceptable salt thereof; an antihypertensive amount of the S(-) enantiomer of amlodipine or of a pharmaceutically acceptable salt thereof and a suitable excipient, diluent or carrier, wherein the enantiomers are present in a ratio by weight (based on free base) of R(+)enantiomer: S(-)enantiomer of greater than 1:1. WO 2004/096770 PCT/GB2004/001638 European patent application 1221438A describe the preparation of two different crystalline forms of amlodipine mesylate. The first described crystal form, referred to as form A, has a melting point of 184+4EC and is described as being essentially water free and as such having a water content of ≤0.2% by weight. The second described crystal form, referred to as form B, has a melting point of 145+3EC and ha a water content of 3.4% by weight and is described as the monohydrate. The preparation of the monohydrate form B from amlodipine free base is described in Example 2. The provision of a monohydrate form of amlodipine, such as for example, amlodipine mesylate monohydrate, can be desirable as monohydrate can exhibit advantageous stability and non-hygroscpic properties, and as such can also exhibit good handling properties. We have now developed an improved process of preparing amlodipine mesylate monohydrate, which can yield a highly pure and stable product. More particularly, there is provided by the present invention a process for preparing amlodipine mesylate monohydrate, which process comprises amlodipine mesylate monohydrate either from anhydrous amlodipine mesylate or in the presence of a water immiscible solvent medium from amlodipine free base and methane sulphonic acid In a first aspect of the present invention wherein amlodipine mesylate monohydrate is prepared Scorn anhydrous amlodipine mesylate, a process according to the present invention comprises dissolving anhydrous amlodipine mesylate in a water miscible solvent medium, and crystallising amlodipine mesylate monohydrate therefrom. Suitably the water miscible solvent medium can comprise one or more lower alcohols, such as any of Cm alcohols. Preferably methanol may be employed in the water miscible solvent medium. The use of methanol can be particularly desirable as it can yield highly pine, stable, white crystalline amlodipine mesylate monohydrate. In a second aspect according to the present invention wherein amlodipine mesylate monohydrate is again prepared from anhydrous amlodipine mesylate, a process according to the present invention comprises exposing anhydrous amlodipine mesylate to an atmosphere saturated with moisture so as to yield amlodipine mesylate monohydrate. In a third aspect according to the present invention wherein amlodipine mesylate monohydrate is prepared from amlodipine free base, suitably the water immiscible WO2004/0S6770 PCT/GB2004/001638 solvent medium comprises ethylether, ethylacetate, dichloromethane or the like, preferably ethyl acetate. It is also generally preferred that a first reaction mixture comprising amlodipine free base dissolved in the water immiscible solvent medium, typically ethyl acetate, is prepared, a second reaction mixture comprising methane sulphonic acid dissolved in a water immiscible solvent medium, again typically ethyl acetate, is prepared, and the first and second reaction mixture are contacted under conditions to yield amlodipine mesylate monohydrate. The present invention will now be illustrated by the following Examples which do not limit the scope of the invention in any way. Figure 1 shows a DSC thermogram of amlodipine mesylate monohydrate as obtained by the following Examples 1,2 and 3. Example 1 Anhydrous amlodipine mesylate 25g was dissolved in a mixture of methanol 50ml and isopropanol 250ml at 50EC and the resulting solution was filtered under nitrogen. The clear filtrate was cooled to 10EC and the resulting crystal filtered. The material was dried under vacuum at 35EC for 4 hours amlodipine mesylate monohydrate 22.4g The water content was about 3.5% Example 2 Anhydrous amlodipine mesylate was exposed to an atmosphere saturated with moisture for 2 to 4 hour* Amlodipine mesylate monohydrate was unloaded and the moisture content thereof was about 3.4%. Examples 3 Amlodipine free base (25gms) was dissolved in ethyl acetate (300ml) at room temperature. 6.25gms of methane sulphonic acid was separately dissolved in 250ml of ethyl acetate. The amlodipine free base solution was cooled to 20EC under a nitrogen blanket and the clear methane sulphonic acid solution was added. The reaction mass was stirred for 1 hour and filtered. The material was dried under vacuum and nitrogen, to yield amlodipine mesylate monohydrate having a moisture content of about 3.32%. WO 2004/096770 PCT/GB2004/001638 Example 4 100 grams of phthaloyl amlodipine is stirred in a mixture of 40% aqueous monomethylamine (700 ml) and dichloromethane (500 ml) at ambient temperature for 12 hours. After reaction completion, the dichloromethane layer is separated and the organic layer is washed with water. The dichloromethane layer is dried over sodium sulfate and distilled to about half the original volume. Ethyl acetate (100 ml) is added and the distillation continue till a total volume of 600 ml is left behind. The content are cooled to 25-30oC. Methane sulfonic acid (18 gm) is dissolved in 100 ml of ethyl acetate and is added to the above solution in 30-45 mins. at 20-25o maintaining an inert atmosphere. Then the content are stirred for 1 hour at 0-5 oC for 30 mins. And filtered to give amlodipine mesylate monohydrate 60 gm Example 5 100 grams of phthaloyl amlodipine is stirred in methanolic monomethylamine (1000 ml) for 12 hour at room temperature. After reaction completion, the reaction mass is distilled to half of its original volume and 1500 ml of dichloromethane is added and further distilled till a total of 500 ml remains in the reaction flask. The dichloromethane layer is washed with water and dried over sodium sulfate. The dichloromethane layer is distilled to half the original volume. 1000 ml ethyl acetate is added and further distilled till 600 ml of solution is retained. The contents are then cooled to 25-30oC. 18 gm of methane sulfonic acid dissolved in 100 ml of ethyl is added to the above solution in 30-45 mins. at 20-25oC under an inert atmosphere. 100 ml methanol and 10 ml purified water are added and warmed to 40-45oC. The contents are then stirred at 25-30oC for 1 hour, cooled and filtered to give amlodipine mesylate monohydrate 55 gm. Example 6 Anhydrous amlodipine mesylate 25 gm was dissolved in a mixture of methanol 25 ml isopropanol 250 ml and water 2.5 ml at 50EC and the resulting solution was filtered. WO 2004/096770 PCT/GB2004/001638 - 6 - under nitrogen. The clear filtrate was cooled to 10EC and the resulting crystals filtered. The material was dried under vacuum at 35EC for 4 hours to give amlodipine mesylate monohydrate 21.8 gm. The water content was about 3.5%. Example 7 Anhydrous amlodipine mesylate 25 gm was dissolved in ethyl acetate 300 ml at 50EC Methanol 20 ml and water added and the resulting solution was filtered under nitrogen. The clear filtrate was cooled to 10EC and the resulting crystals filtered. The material was dried under vacuum at 35EC for 4 hours to give amlodipine mesylate monohydrate. The water content about 3.6% Example 8 Anhydrous amlodipine mesylate 50 gm was dissolved in methanol 150 ml and water 20 ml. Methanol was distilled off and simultaneously replaced with an equal quantity of acetone. When crystals filtered. When crystals began to appear, the distillation was stopped and the contents cooled to 10oC and the crystals filtered. The material was dried under vacuum at 35EC for 4 hours to give amlodipine mesylate monohydrate 43 g,. The water content was about 3.4%. Abstract Amlodipine mesylate monohydrate is prepared either from anhydrous amlodipine mesylate, or in the presence of a water immiscible solvent medium from amlodipine free base and methane suphonic acid. We claim: - 7 - 1. A process for preparing amlodipine mesylate monohydrate, which process comprises preparing amlodipine mesylate monohydrate from amlodipine free base and methane sulphonic acid in the presence of ethyl acetate. 2. A process according to claim 1, wherein a first reaction mixture comprising amlodipine free base dissolved in ethyl acetate is prepared, a second reaction mixture comprising methane sulphonic acid dissolved In a water Immiscible solvent medium is prepared, and the first and second reaction mixtures are contacted under conditions to yield amlodipine mesylate monohydrate. 3. A process according to claim 2, wherein the water-Immiscible solvent is ethyl acetate. 4. A process according to claims 2 or 3, wherein the first reaction mixture is cooled to 20°C under a nitrogen blanket 5. A process according to claims 2, 3 or 4, wherein the first and second reaction mixtures are contacted and stirred for 1 hour. 6. A process according to any preceding claim, wherein the amlodipine mesylate monohydrate is isolated by filtration. 7. A process according to any preceding claim, wherein the amlodipine mesylate monohydrate Is dried under vacuum. 8. A process for preparing amlodipine mesylate monohydrate substantially as herein described with reference to the foregoing examples and accompanying drawing.

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“PROCESS FOR PREPARING ALMODIPINE MESYLATE
MONOHYDRATE”
CIPLA LIMITED of 289 Bellasis Road, Mumbai Central, Mumbai 400 008, India.
The following specification particularly describes the invention and the manner in which it is to be performed.

WO 2004/096770
PCT/GB2004/001638
-2-
PROCESS FOR PREPARING ALMODIPINS MESYLATE MONOHXDRATE
The present invention is concerned with a process for preparing amlodipine mesylate monohydrate.
Amlodipine is the international non-proprietary name of 2-f(2-Aminoethoxy)-
methyl]-4-(2-chlorophenyl),4-dihydro-6-methyl-3,5-pyridinecarboxilic acid 3-ethyl 5- methyl ester. Amlodipine is known to be a calcium channel blocker and has therapeutic applications in the treatment or prevention of a number of cardiac conditions, such as angina pectoris, cardiac antihypertensive, heart attacks, cardiac hypertrophy and related cardiac conditions, and also as an antihypertensive agent, for example in the treatment of coronary vasospasm.
Amlodipine is the title compound of Example 9 of European Patent 008P167B and its preparation is described therein, European Patent 0089167B describes suitable pharmaceutically acceptable salts of the compounds described therein, including the hydrochloride, hydrobromide, sulphate, phosphate or acid phosphate, acetate, maleate, fumarate, lactate, tartrate, citrate and gluconate salts. Maleate is described as the preferred salt The preparation of the maleate salt of amlodipine is described in Examples 11 and 12 of European Patent 0089167B.
European Patent Application 0244944A describes further salts of amlodipine, and describes the besylate salt of amlodipine as being a particularly preferred salt
US Patent 6057344 describes the use of (-)amlodipine, substantially tree of its (+) stereoisomer, in eliciting an antihypertensive effect and also for use in the treatment of angina. Preferred pharmaceutically acceptable salts described in US Patent 6057344 are derived from besylate, hydrobromic, hydrochloric, phosphoric and sulphuric acids.
US Patent Application 2002/0045648 describes a pharmaceutical composition comprising an NO-releasing amount of the R(+)enantiomer of amlodipine or of a pharmaceutically acceptable salt thereof; an antihypertensive amount of the S(-) enantiomer of amlodipine or of a pharmaceutically acceptable salt thereof and a suitable excipient, diluent or carrier, wherein the enantiomers are present in a ratio by weight (based on free base) of R(+)enantiomer: S(-)enantiomer of greater than 1:1.

WO 2004/096770
PCT/GB2004/001638

European patent application 1221438A describe the preparation of two different crystalline forms of amlodipine mesylate. The first described crystal form, referred to as form A, has a melting point of 184+4EC and is described as being essentially water free and as such having a water content of ≤0.2% by weight. The second described crystal form, referred to as form B, has a melting point of 145+3EC and ha a water content of 3.4% by weight and is described as the monohydrate. The preparation of the monohydrate form B from amlodipine free base is described in Example 2.
The provision of a monohydrate form of amlodipine, such as for example, amlodipine mesylate monohydrate, can be desirable as monohydrate can exhibit advantageous stability and non-hygroscpic properties, and as such can also exhibit good handling properties. We have now developed an improved process of preparing amlodipine mesylate monohydrate, which can yield a highly pure and stable product.
More particularly, there is provided by the present invention a process for preparing amlodipine mesylate monohydrate, which process comprises amlodipine mesylate monohydrate either from anhydrous amlodipine mesylate or in the presence of a water immiscible solvent medium from amlodipine free base and methane sulphonic acid
In a first aspect of the present invention wherein amlodipine mesylate monohydrate is prepared Scorn anhydrous amlodipine mesylate, a process according to the present invention comprises dissolving anhydrous amlodipine mesylate in a water miscible solvent medium, and crystallising amlodipine mesylate monohydrate therefrom.
Suitably the water miscible solvent medium can comprise one or more lower alcohols, such as any of Cm alcohols. Preferably methanol may be employed in the water miscible solvent medium. The use of methanol can be particularly desirable as it can yield highly pine, stable, white crystalline amlodipine mesylate monohydrate.
In a second aspect according to the present invention wherein amlodipine mesylate monohydrate is again prepared from anhydrous amlodipine mesylate, a process according to the present invention comprises exposing anhydrous amlodipine mesylate to an atmosphere saturated with moisture so as to yield amlodipine mesylate monohydrate.
In a third aspect according to the present invention wherein amlodipine mesylate monohydrate is prepared from amlodipine free base, suitably the water immiscible

WO2004/0S6770 PCT/GB2004/001638

solvent medium comprises ethylether, ethylacetate, dichloromethane or the like, preferably ethyl acetate. It is also generally preferred that a first reaction mixture comprising amlodipine free base dissolved in the water immiscible solvent medium, typically ethyl acetate, is prepared, a second reaction mixture comprising methane sulphonic acid dissolved in a water immiscible solvent medium, again typically ethyl acetate, is prepared, and the first and second reaction mixture are contacted under conditions to yield amlodipine mesylate monohydrate.

The present invention will now be illustrated by the following Examples which do not limit the scope of the invention in any way.

Figure 1 shows a DSC thermogram of amlodipine mesylate monohydrate as obtained by the following Examples 1,2 and 3.

Example 1

Anhydrous amlodipine mesylate 25g was dissolved in a mixture of methanol 50ml and isopropanol 250ml at 50EC and the resulting solution was filtered under nitrogen. The clear filtrate was cooled to 10EC and the resulting crystal filtered. The material was dried under vacuum at 35EC for 4 hours amlodipine mesylate monohydrate 22.4g The water content was about 3.5%

Example 2
Anhydrous amlodipine mesylate was exposed to an atmosphere saturated with moisture for 2 to 4 hour* Amlodipine mesylate monohydrate was unloaded and the moisture content thereof was about 3.4%.
Examples 3
Amlodipine free base (25gms) was dissolved in ethyl acetate (300ml) at room temperature. 6.25gms of methane sulphonic acid was separately dissolved in 250ml of ethyl acetate. The amlodipine free base solution was cooled to 20EC under a nitrogen blanket and the clear methane sulphonic acid solution was added. The reaction mass was stirred for 1 hour and filtered. The material was dried under vacuum and nitrogen, to yield amlodipine mesylate monohydrate having a moisture content of about 3.32%.

WO 2004/096770
PCT/GB2004/001638

Example 4
100 grams of phthaloyl amlodipine is stirred in a mixture of 40% aqueous monomethylamine (700 ml) and dichloromethane (500 ml) at ambient temperature for 12 hours. After reaction completion, the dichloromethane layer is separated and the organic layer is washed with water. The dichloromethane layer is dried over sodium sulfate and distilled to about half the original volume. Ethyl acetate (100 ml) is added and the distillation continue till a total volume of 600 ml is left behind. The content are cooled to 25-30oC.
Methane sulfonic acid (18 gm) is dissolved in 100 ml of ethyl acetate and is added to the above solution in 30-45 mins. at 20-25o maintaining an inert atmosphere. Then the content are stirred for 1 hour at 0-5 oC for 30 mins. And filtered to give amlodipine mesylate monohydrate 60 gm

Example 5
100 grams of phthaloyl amlodipine is stirred in methanolic monomethylamine (1000 ml) for 12 hour at room temperature. After reaction completion, the reaction mass is distilled to half of its original volume and 1500 ml of dichloromethane is added and further distilled till a total of 500 ml remains in the reaction flask. The dichloromethane layer is washed with water and dried over sodium sulfate. The dichloromethane layer is distilled to half the original volume. 1000 ml ethyl acetate is added and further distilled till 600 ml of solution is retained. The contents are then cooled to 25-30oC.
18 gm of methane sulfonic acid dissolved in 100 ml of ethyl is added to the above solution in 30-45 mins. at 20-25oC under an inert atmosphere. 100 ml methanol and 10 ml purified water are added and warmed to 40-45oC. The contents are then stirred at 25-30oC for 1 hour, cooled and filtered to give amlodipine mesylate monohydrate 55 gm.

Example 6
Anhydrous amlodipine mesylate 25 gm was dissolved in a mixture of methanol 25 ml isopropanol 250 ml and water 2.5 ml at 50EC and the resulting solution was filtered.

WO 2004/096770
PCT/GB2004/001638
- 6 -

under nitrogen. The clear filtrate was cooled to 10EC and the resulting crystals filtered. The material was dried under vacuum at 35EC for 4 hours to give amlodipine mesylate monohydrate 21.8 gm. The water content was about 3.5%.

Example 7
Anhydrous amlodipine mesylate 25 gm was dissolved in ethyl acetate 300 ml at 50EC Methanol 20 ml and water added and the resulting solution was filtered under nitrogen. The clear filtrate was cooled to 10EC and the resulting crystals filtered. The material was dried under vacuum at 35EC for 4 hours to give amlodipine mesylate monohydrate. The water content about 3.6%

Example 8

Anhydrous amlodipine mesylate 50 gm was dissolved in methanol 150 ml and water 20 ml. Methanol was distilled off and simultaneously replaced with an equal quantity of acetone. When crystals filtered. When crystals began to appear, the distillation was stopped and the contents cooled to 10oC and the crystals filtered. The material was dried under vacuum at 35EC for 4 hours to give amlodipine mesylate monohydrate 43 g,. The water content was about 3.4%.
Abstract
Amlodipine mesylate monohydrate is prepared either from anhydrous amlodipine mesylate, or in the presence of a water immiscible solvent medium from amlodipine free base and methane suphonic acid.

We claim:

- 7 -

1. A process for preparing amlodipine mesylate monohydrate, which process comprises preparing amlodipine mesylate monohydrate from amlodipine free base and methane sulphonic acid in the presence of ethyl acetate.
2. A process according to claim 1, wherein a first reaction mixture comprising amlodipine free base dissolved in ethyl acetate is prepared, a second reaction mixture comprising methane sulphonic acid dissolved In a water Immiscible solvent medium is prepared, and the first and second reaction mixtures are contacted under conditions to yield amlodipine mesylate monohydrate.
3. A process according to claim 2, wherein the water-Immiscible solvent is ethyl acetate.
4. A process according to claims 2 or 3, wherein the first reaction mixture is cooled to 20°C under a nitrogen blanket
5. A process according to claims 2, 3 or 4, wherein the first and second reaction mixtures are contacted and stirred for 1 hour.
6. A process according to any preceding claim, wherein the amlodipine mesylate
monohydrate is isolated by filtration.
7. A process according to any preceding claim, wherein the amlodipine mesylate monohydrate Is dried under vacuum.
8. A process for preparing amlodipine mesylate monohydrate substantially as herein described with reference to the foregoing examples and accompanying drawing.

Documents:

1218-MUMNP-2005-ABSTRACT(6-11-2008).pdf

1218-mumnp-2005-abstract.doc

1218-mumnp-2005-abstract.pdf

1218-mumnp-2005-cancelled pages(06-11-2008).pdf

1218-MUMNP-2005-CANCELLED PAGES(6-11-2008).pdf

1218-MUMNP-2005-CLAIMS(6-11-2008).pdf

1218-mumnp-2005-claims(granted)(06-11-2008).pdf

1218-mumnp-2005-claims(granted)-(06-11-2008).doc

1218-mumnp-2005-claims.doc

1218-mumnp-2005-claims.pdf

1218-mumnp-2005-correspondence(06-11-2008).pdf

1218-MUMNP-2005-CORRESPONDENCE(6-11-2008).pdf

1218-mumnp-2005-correspondence(ipo)-(26-12-007).pdf

1218-mumnp-2005-correspondence-received.pdf

1218-mumnp-2005-descripiton (complete).pdf

1218-MUMNP-2005-DESCRIPTION(COMPLETE)-(6-11-2008).pdf

1218-mumnp-2005-drawing(06-11-2008).pdf

1218-MUMNP-2005-DRAWING(6-11-2008).pdf

1218-mumnp-2005-drawings.pdf

1218-mumnp-2005-form 1(06-11-2008).pdf

1218-MUMNP-2005-FORM 1(28-10-2005).pdf

1218-mumnp-2005-form 13(27-10-2005).pdf

1218-mumnp-2005-form 13(31-12-2008).pdf

1218-mumnp-2005-form 18(18-04-2006).pdf

1218-mumnp-2005-form 2(6-11-2008).pdf

1218-mumnp-2005-form 2(granted)-(06-11-2008).doc

1218-mumnp-2005-form 2(granted)-(06-11-2008).pdf

1218-MUMNP-2005-FORM 2(TITLE PAGE)-(6-11-2008).pdf

1218-mumnp-2005-form 26(05-11-2008).pdf

1218-mumnp-2005-form 26(27-10-2005).pdf

1218-MUMNP-2005-FORM 26(28-10-2005).pdf

1218-mumnp-2005-form 3(02-02-2006).pdf

1218-mumnp-2005-form 3(06-11-2008).pdf

1218-mumnp-2005-form 3(27-10-2005).pdf

1218-MUMNP-2005-FORM 3(6-11-2008).pdf

1218-mumnp-2005-form 5(27-10-2005).pdf

1218-mumnp-2005-form-1.pdf

1218-mumnp-2005-form-13.pdf

1218-mumnp-2005-form-2.doc

1218-mumnp-2005-form-2.pdf

1218-mumnp-2005-form-26.pdf

1218-mumnp-2005-form-3.pdf

1218-mumnp-2005-form-5.pdf

1218-mumnp-2005-form-pct-ib-304.pdf

1218-MUMNP-2005-RECEIPT(IPO)-(6-11-2008).pdf

abstract1.jpg

« Previous Patent

Next Patent »

Patent Number

226948

Indian Patent Application Number

1218/MUMNP/2005

PG Journal Number

10/2009

Publication Date

06-Mar-2009

Grant Date

31-Dec-2008

Date of Filing

28-Oct-2005

Name of Patentee

CIPLA LIMITED

Applicant Address

289 BELLASIS ROAD, MUMBAI CENTRAL, MUMBAI - 400 008

Inventors:

#	Inventor's Name	Inventor's Address
1	SRINIVAS PATHI L	2475/24, 7TH B MAIN, RPC LAYOUT, VIJAYANAGAR, BANGALORE 560 040
2	KANKAN RAJENDRA NARAYANRAO	A-3/5, NBD SOCIETY, NSS ROAD, GHATKOPAR (WEST), MUMBAI 400 084
3	RAO DHARMARAJ RAMACHANDRA	4/403 Garden Enclave, Pokharan Road 2, Thane West, Mumbai 400 061

PCT International Classification Number

C07D211/90

PCT International Application Number

PCT/GB2004/001638

PCT International Filing date

2004-04-16

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0309471.1	2003-04-25	U.K.
2	0314617.2	2003-06-23	U.K.