DESC:FIELD OF THE INVENTION
The present invention relates to an improved process for preparing highly pure donepezil hydrochloride.

BACKGROUND OF THE INVENTION
Donepezil hydrochloride, which is chemically known as 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl)methyl piperidine hydrochloride and represented by formula I,

Formula I
is used in the treatment of Alzheimer's disease where it is used to increase cortical acetylcholine. It is available for oral administration in film-coated tablets containing 5 or 10 mg of donepezil hydrochloride.

Donepezil was first disclosed in US Patent 4,895,841. Thereafter, several processes for the preparation of donepezil and its pharmaceutically acceptable salts have published. In US patent 4,895,841, 5,6-dimethoxy-l-indanone is condensed with 1- benzylpiperidine-4-carboxaldehyde in the presence of strong base, such as lithium diisopropylamide (LDA) to prepare a 1-benzyl-4-[(5,6-dimethoxy-1- indanon)-2-ylidenyl]methyl piperidine of Formula II,

Formula II
which on reduction in the presence of palladium on carbon in tetrahydrofuran yield donepezil.
There are significant drawbacks to this method as the catalytic hydrogenation of the 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine of Formula II to the corresponding compound of Formula I, results in the debenzylation leading in the formation of following impurity of Formula III, in substantial amounts,

Formula III
which is difficult to remove. The above impurity is further carried into donepezil hydrochloride. The generation of significant quantity of debenzylated impurity during hydrogenation makes the process uneconomical. In the exemplified process given in US Patent 4,895,841, column chromatography is utilized to purify the product which is not amenable on industrial scale.

PCT Publication No. WO2008/010235 disclosed a method for preparation of donepezil hydrochloride wherein 1-benzyl-4-[(5,6-dimethoxy-1-indanon)- 2-ylidenyl]methyl piperidine is reduced with metal borohydride in the presence of a catalytic amount of a cobalt salt in a large volume of THF as solvent to yield donepezil hydrochloride. This process is not viable industrially due to use of costly cobalt catalyst and use of large volume of solvent.

PCT Publication No. WO2009/084030 disclosed a method for preparation of donepezil hydrochloride wherein crude 1-benzyl-4-[(5,6-dimethoxy-1-indanon)- 2-ylidenyl]methyl piperidine hydrochloride salt is purified with methanol, acetone solvents and followed by reduction of the purified compound with 5% Pd-C (50% wet) in presence of acetic acid, methanol results crude compound. The resulting crude is extracted with methylene chloride in presence of base and followed by acidification, distillation of organic layer results another crude compound. The said crude compound is converted to donepezil free base by dissolving the crude in purified water and methanol. The pH of the resulting mixture is adjusted with base to obtain donepezil free base. The isolated donepezil free base is converted to donepezil hydrochloride with isopropanolic hydrochloride.
The said PCT suffers from the drawback such as isolation of donepezil free base by the method as described herein above makes the process lengthy and eventually adds on the cost.

U.S. Patent No. US8,987,458, disclosed preparation of donepezil hydrochloride by reducing 1-benzyl-4-[(5,6-dimethoxy-1-indanon-2-yl)methylene]pyridonium halide, represented by the following structure,

wherein X is chloride or bromide
with platinum catalyst in the presence of ionic compound viz. ammonium acetate, a solvent, and a source of hydrogen. After the reduction reaction, a residue is obtained which is stirred with water and the pH of the reaction mass was adjusted to 7.5-8.0 using liquor ammonia and the solid was extracted with ethyl acetate thrice. The ethyl acetate layer is dried, distilled to give a crude i.e. donepezil free base. The donepezil free base is converted to donepezil hydrochloride by using methanolic hydrochloride with pH adjustment of the reaction mass to 2.0-2.5.
The main objective of the said patent is to minimize the formation of the impurity, having following structure, by using ammonium acetate.

The said US patent suffers from the drawback such as isolation of donepezil free base involving lengthy extraction process and use of ionic compound viz. ammonium acetate during reduction reaction eventually adds on the cost.

Indian application publication No. IN677/MUM/2006 disclosed preparation of donepezil hydrochloride wherein 1-benzyl-4-[(5,6-dimethoxy-1-indanon)- 2-ylidenyl]methyl piperidine is treated with sodium dithionite in water and in presence of tetrabutyl ammonium bromide, methylene chloride as reaction solvent at 42-45°C to get a reaction mixture. The reaction mixture maintained at 42-45°C for 20-24 hours and product enriched methylene chloride layer is separated, treated with aqueous hydrochloric acid to give donepezil hydrochloride. The resulting donepezil hydrochloride, having nil olefinic impurity, represented by the following structure.

The said Indian application suffers from the drawback such as use of sodium dithionite, tetrabutyl ammonium bromide during reduction reaction eventually adds on the cost and completion of reduction reaction takes a long time viz. 20-24 hours makes the process lengthy.

Indian application publication No. IN2947/MUM/2009 disclosed preparation of donepezil hydrochloride wherein 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine is reduced with 10% palladium on carbon under hydrogen pressure to give a residue. The said residue is purified with lengthy process that is layer separation, acidification, basification and isolating the residue. Then, the resulting residue is converted to donepezil hydrochloride by using concentrated hydrochloric acid (pH 2-3) in presence of aqueous isopropanol solvent.
The said Indian application suffers from the drawback such as purification of residue with lengthy process that is layer separation, acidification, basification and isolating the residue eventually adds on the cost.

Indian patent no. IN268394 disclosed preparation of donepezil hydrochloride wherein 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine is reduced with 5 % platinum on carbon in presence of ethyl acetate and donepezil free base is isolated as residue. The resulting residue is converted to donepezil hydrochloride by using ethyl acetate hydrochloride.
The said patent belongs to the applicant of the present invention and there is a scope of improvisation over the said Indian patent which is depicted clearly from the disclosure of the present invention.
In the above prior art references, pure donepezil hydrochloride is prepared via isolation of crude donepezil free base (obtained after reduction reaction) either by separation of organic layer followed by concentration or by concentration of filtrate in vacuum. Further, the resulting crude donepezil free base is converted to donepezil hydrochloride in presence of organic solvent. Furthermore, most of the references of the prior art don’t suggest or teach any solution for the removal of impurity of Formula III, obtained during hydrogenation step.
Therefore, the prior art processes for preparing pure donepezil hydrochloride are complex, lengthy and there is an urgent need to develop an improved robust process for preparing highly pure donepezil hydrochloride having negligible or non-detectable impurities.

OBJECT OF THE INVENTION
The principal object of the present invention is to provide an improved process for preparing highly pure donepezil hydrochloride.
Another object of this invention is to provide a process for preparing highly pure donepezil hydrochloride from 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine or acid addition salts thereof.
Yet another objective of the present invention is to provide a process for preparing highly pure donepezil hydrochloride from pure intermediate viz. hydrochloride salt of 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methyl piperidine.

SUMMARY OF THE INVENTION
One aspect of the present invention is to provide an improved process for preparing highly pure donepezil hydrochloride of Formula I,

Formula I
comprises:
i) reducing 1-benzyl-4-[(5,6-dimethoxy-1-indanon)- 2-ylidenyl]methyl piperidine of Formula II,

Formula II
by using platinum on carbon in presence of chlorinated solvent to obtain a reaction mixture comprising donepezil;
ii) adding water, hydrochloric acid to the reaction mixture of step i) and
iii) isolating highly pure donepezil hydrochloride of Formula I.

In another aspect, the present invention is to provide an improved process for preparing highly pure donepezil hydrochloride of Formula I,

Formula I
comprises:
i) reacting 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine of Formula II,

Formula II
with source of hydrochloride to give crude hydrochloride salt of formula II,
ii) purifying the crude hydrochloride salt of formula II with alcoholic solvent to obtain pure hydrochloride salt of formula II and
iii) converting pure hydrochloride salt of formula II to highly pure donepezil hydrochloride.

DETAILED DESCRIPTION OF THE INVENTION
The term "highly pure" used herein means a chemical or chromatographic (area % HPLC) purity of at least 99.0 %, preferably at least 99.90%, more preferably at least 99.94% and/or single highest unknown impurity is not more than 0.05% and total impurities are not more than 0.06% by high-performance liquid chromatography (HPLC).
The term includes a purity reaching up to practically 100.0 area % chromatographic purity in which some impurities if detected are in traces and/or below limit of quantitation/detection.
The instant invention relates to an improved, efficient and industrially advantageous process for preparing highly pure donepezil hydrochloride of Formula I.
According to an embodiment, there is provided a process for preparing highly pure donepezil hydrochloride of Formula I by reducing 1-benzyl-4-[(5,6- dimethoxy-1-indanon)-2-ylidenyl]methyl piperidine of Formula II.
The Formula II is reduced by using platinum on carbon in presence of chlorinated solvent to obtain a reaction mixture comprising donepezil.
The chlorinated solvent used in the reduction reaction is selected from methylene chloride, ethylene chloride and alike or mixture thereof.
Specifically, hydrogenation/reduction of Formula II is carried out at 15°C to 40°C preferably at 20°C to 35°C under 1-5 atmospheric pressure preferably at 3.8-4.2 atmospheric pressure for 3 to 8 hours.
The donepezil, present in reaction mixture, is in-situ converted to highly pure donepezil hydrochloride by adding water, concentrated hydrochloric acid to the reaction mixture comprising donepezil at a temperature 15°C to 40°C.
After addition of the acid, pH of the reaction mixture becomes 0.2-1.5 and layers are separated. The aqueous layer is extracted by methylene chloride and combined methylene chloride layers are distilled out to get a crude donepezil hydrochloride.
The inventors of the present invention have surprisingly observed that the addition of hydrochloric acid to get pH of reaction mixture in the range of 0.2-1.5 plays an important role in removing impurities and in isolating pure donepezil hydrochloride. When the pH of reaction mixture is in the range of 0.2-1.5, then, the donepezil hydrochloride presents in the aqueous layer changes its phase from aqueous to organic layer and impurities remain in the aqueous layer in hydrochloride salt form.
Usually, hydrochloride salt bounded compound remains in aqueous layer until it is in form of hydrochloride salt and therefore, it isolated from aqueous layer. However, the present inventors surprisingly observed that the phase of donepezil hydrochloride is changed from aqueous to organic layer at pH range of 0.2-1.5 and the impurity of Formula III and/or other impurities in form of hydrochloride salt remain in aqueous layer at the said pH range.
The crude donepezil hydrochloride is further purified to obtain highly pure donepezil hydrochloride of Formula I. The purification may be done by any technique known in the prior art such as crystallization, washing, precipitation, evaporation of solvent and/or combination of the said techniques.
In one embodiment, the crude donepezil hydrochloride is purified by crystallization with methanol followed by isopropyl ether and recrystallized with methanol, water followed by isopropyl ether to obtain highly pure donepezil hydrochloride monohydrate.
According to an embodiment, the highly pure donepezil hydrochloride of Formula I prepared by the present invention may be isolated as monohydrate or as anhydrous form.
According to one aspect of the present invention, the highly pure donepezil hydrochloride of Formula I has 4.5-6 % water content (monohydrate), yield greater than 75% and characterized by XRD which matches with prior art polymorphic Form 1 of donepezil hydrochloride monohydrate.
In other embodiment, donepezil hydrochloride monohydrate (Form I) may be converted to anhydrous donepezil hydrochloride (Form III), wherein water content is not more than 0.2 % w/w.

According to an embodiment, the highly pure donepezil hydrochloride of Formula I prepared by the present invention may be converted to highly pure donepezil free base. In the process, the highly pure donepezil hydrochloride is treated with a base in the presence of solvent such as ester solvent, chlorinated solvent to give donepezil free base. Donepezil free base is isolated from the reaction mixture by extraction method or any other methods known in the prior art. The extracted product is further purified with alcoholic solvent selected from methanol, ethanol and isopropanol to get highly pure donepezil free base.

In another aspect of the present invention is to provide an improved process for preparing highly pure donepezil hydrochloride of Formula I from pure intermediate viz. hydrochloride salt of 1-benzyl-4-[(5,6-dimethoxy-1-indanon-2-ylidenyl]methyl piperidine of Formula II.
The hydrochloride salt of 1-benzyl-4-[(5,6-dimethoxy-1-indanon-2-ylidenyl] methyl piperidine of Formula II is prepared by reacting 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine of Formula II with source of hydrochloride to give crude hydrochloride salt of formula II.
Generally, 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine of Formula II, having hydroxy impurity of Formula IV,

Formula IV
is treated with organic or inorganic acid in the presence of solvent such as ethers, alcohols, ketones, hydrocarbons, polar aprotic solvents. Specifically, the Formula II is treated with methanolic-hydrochloride in methanol. After work up and purification of crude hydrochloride salt of Formula II with alcohol solvent the pure hydrochloride salt of Formula II is isolated, which is then basified or optionally purified to get 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl] methyl piperidine of Formula II.
The alcohol solvent used in the purification are selected from aliphatic or branched chain alcohols, preferably selected from methanol, ethanol, isopropanol and/or mixture thereof.
In the present invention, the crude hydrochloride salt of formula II is purified by slurry wash of the crude in alcohol solvent at 35 °C to 55 °C for 30 minutes to 5 hours and then cool the reaction mixture at 5 °C to 25 °C to obtain pure hydrochloride salt of Formula II. Further, the pure hydrochloride salt of Formula II is converted to highly pure donepezil hydrochloride by the process of the present invention or by the processes known in the prior art or by the present invention as discussed herein above.
The alcohol solvent used in slurry washing may be selected from aliphatic or branched chain alcohols, preferably selected from methanol, ethanol, isopropanol and/or mixture thereof.
The pure hydrochloride salt of formula II is referred to hydrochloride salt of formula II having purity of at least 99.0 %, preferably at least 99.90% and having hydroxy impurity not more than 0.05%.
The pure hydrochloride salt of Formula II prepared by the present invention may be characterized by analytical techniques known in the prior art are selected from but not limited to X-ray crystallography (XRD), differential scanning calorimetry (DSC), infrared spectroscopy (IR) and melting point.
The 1-benzyl-4-[(5,6-dimethoxy-1-indanon-2-ylidenyl]methylpiperidine of Formula II, used in the present invention for preparing its hydrochloride salt, can be prepared by any method known in the prior art or by the process of the present invention, wherein 5,6-dimethoxy indanone is coupled with 1-benzylpiperidine-4-carboxaldehyde in presence of sodium methoxide in catalytic amount and using chlorinated solvents. In the said coupling the sodium methoxide is used in catalytic amount, wherein 0.2 to 0.9 mol equivalent of sodium methoxide is used w.r.t. 5,6-dimethoxy indanone.
The purity of product/intermediate, reaction completion and monitoring of the reaction of the present invention is checked by any analytical techniques known in the prior art such as high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), gas chromatography (GC) and alike.

Having described the invention with reference to certain preferred aspects, other aspects will become apparent to one skilled in the art from consideration of the specification. The invention is further defined by reference to the following examples describing in detail by the preparation of highly pure donepezil hydrochloride of Formula I.

Example 1: Process for preparing 1-benzyl-4-[(5,6-dimethoxy-1-indanon) -2-ylidenyl]methyl piperidine of Formula II
a) Process for preparing hydrochloride salt of Formula II
To a solution of 5,6-dimethoxy indanone (100g) in methylene chloride (500 ml) were added 1-benzylpiperidine-4-carboxaldehyde (132.0g, 1.25 eq.) and sodium methoxide (14.0g, 0.5 eq.). The resulting reaction mixture was stirred at 38-42°C for 4.0 hours. After the completion of reaction [monitored by HPLC], the reaction mixture was distilled and degassed under vacuum to give a crude. Methanol was added (200.0 ml) to the crude and reaction mixture was stirred. The solvent was distilled at temperature below 45°C. Then, methanol (300.0 ml) was added into the resulting crude and reaction mixture was stirred for 1.0 hour at temperature of 40-45°C. Further, the reaction mixture was cooled to 15-20°C and stirred for 30 minutes. The solid thus obtained was filter out and washed with methanol (100 ml). The obtained wet solid was charged in reactor, added methanol (600 ml) and stirred for 15-20 minutes at temperature of 35-40°C. Then, methanolic hydrochloride (140 ml) was added to bring pH<1.0 at temperature of 35-45°C and resulting reaction mixture was stirred for 4.0 hour. The solvent was distilled out completely under vacuum below 50°C to obtain hydrochloride salt of Formula II.
b) Purification of hydrochloride salt of Formula II
Methanol (300 ml) was added to the above obtained hydrochloride salt of Formula II and the reaction mixture was stirred for 1.0 hour at temperature of 40-45°C. Then, the reaction mixture was cooled to temperature of 10-15°C and stirred for 1.0 hour. The reaction mixture was filtered and resulting wet solid was washed with methanol (300 ml) under stirring and filtered solid and suck dried. The solid was again washed with methanol (50 ml) and suck dried to get pure hydrochloride salt of Formula II, having hydroxy impurity <0.05%).
c) Process for preparing 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl] methyl piperidine of Formula II
Wet solid was charged in clean reactor and added methylene chloride (800 ml). Stirred the mass and DM water (1.0 L) was added. The reaction mass was cooled to 20-25oC, pH was adjusted to 9.0-10 with 10% NaOH solution (1.9 L). Stirred and settled the reaction mass. The layers were separated and the aqueous layer was extracted twice with methylene chloride (2x200 ml). The combined organic layer was washed twice with DM water (2x400 ml). Distilled out solvent under atmospheric pressure and degassed under vacuum at temperature below 45°C. Methanol (200 ml) was added into reaction mass, stirred and distilled out the reaction mixture below 50°C. Methanol (400 ml) was charged, stirred the reaction mass for 1.0h at temperature 35-40°C and further cooled to 15-20°C. Stirred the mass for 30 minutes at temperature 15-20°C. Filtered out the solid and suck dried. Washed the solid with methanol (100 ml) and dried the material to obtain the 172.5 g of the titled compound.
Purity 100% by HPLC, Water content 0.08%w/w, Hydroxy impurity =0.05% and Unknown impurity =0.06%.
Example 2: Preparation of highly pure donepezil Hydrochloride with in-situ preparation of donepezil free base
To a solution of 1-benzyl-4-[5,6-dimethoxy-1-indanon)-2-ylidenyl]methyl piperidine (140g) in methylene chloride (700ml) was charged 5% Pt/C (28g, 0.2T) and the resulting reaction mixture was stirred under hydrogen pressure 3.8-4.2 kg/cm2 at 25-34°C for 7 hour. After completion of reaction [monitored by HPLC], the catalyst was filtered out and washed with methylene chloride (280 ml). Then, water (700 ml) was added to the filtrate to give reaction mixture. The pH of the reaction mixture was adjusted to 0.5-1.0 with concentrated HCl (0.40-0.45V) at temperature of 20-25°C under stirring. The layers were separated and the aqueous layer was extracted with methylene chloride (2x280 ml) at temperature of 25-30oC. The combined organic layer was distilled out under atmospheric pressure and degassed under vacuum to get a residue. Methanol was added (280 ml) to the residue and stirred. The solvent was distilled out completely under vacuum at temperature below 50°C and methanol was added (700 ml) to the resulting residue. The reaction mixture was stirred and heated at temperature of 50-55oC to get clear solution. The solution was cooled to 20-30oC and filtered isopropyl ether (2.1L) was added slowly into the solution. The obtained solid was filtered immediately after isopropyl ether addition. Washed the solid with isopropyl ether (140 ml) and suck dried. Wet solid was charged in clean reactor, methanol (644 ml) and water (62.72 ml) were added, heated, and stirred the reaction mixture at temperature of 45-50°C to get clear solution. Filtered the solution through hyflo and washed with methanol (84 ml). Filtrate was charged in clean reactor and cooled to 0-8°C. Filtered isopropyl ether (1.68L) was added slowly into reaction mixture, stirred for 40 minutes at temperature of 0-5°C. Filtered out the material and suck dried. Unloaded the wet solid and dried in STD oven at temperature of 25-30°C for 16 hours to obtained 125.5g (78%) of donepezil hydrochloride monohydrate [water content 5.2% w/w] having purity 100.0% by HPLC; any unspecified impurity: not deducted and total impurities: were below disregard limit.
Reference Example [IN268394]: Preparation of pure donepezil Hydrochloride with isolation of donepezil free base
1-benzy-4-[5,6-dimethoxy-1-indanon)-2-ylidenyl]methy]piperidine (10g) was hydrogenated in ethyl acetate (100 ml) for 2 hours in presence of 5% platinum- carbon (2g) at 4 atmospheric pressure. The reaction mixture was filtered and concentrated under vacuum to give residue (donepezil free base).
The residue was dissolved in methylene chloride and further acidified with a solution ethyl acetate hydrochloric acid at 0-10°C followed by concentration in vacuum to obtain a solid which was recrystallized from methanol and isopropyl ether to obtain 7.4 g of 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl] methylpiperidine hydrochloride (yield 67%) having a purity of 99.93% by HPLC.
,CLAIMS:WE CLAIM:
Claim 1. An improved process for preparing highly pure donepezil hydrochloride of Formula I,

Formula I
comprises:
i) reducing 1-benzyl-4-[(5,6-dimethoxy-1-indanon)- 2-ylidenyl]methyl piperidine of Formula II,

Formula II
by using platinum on carbon in presence of chlorinated solvent to obtain a reaction mixture comprising donepezil;
ii) adding water, hydrochloric acid to the reaction mixture of step i) and
iii) isolating highly pure donepezil hydrochloride of Formula I.

Claim 2. The process as claimed in claim 1, wherein chlorinated solvent are selected from methylene chloride, ethylene chloride and alike or mixture thereof.
Claim 3. The process as claimed in claim 1, wherein reduction of Formula II is carried out at 15°C to 40°C and under 1-5 atmospheric pressure for 3 to 8 hours.
Claim 4. The process as claimed in claim 1, wherein step i) reaction mixture comprising donepezil is in-situ converted to highly pure donepezil hydrochloride by adding water, concentrated hydrochloric acid to the reaction mixture comprising donepezil at a temperature 15°C to 40°C.

Claim 5. The process as claimed in claim 1, wherein the pH of the reaction mixture is 0.2-1.5 after addition of hydrochloric acid at step ii).

Claim 6. An improved process for preparing highly pure donepezil hydrochloride of Formula I,

Formula I
comprises:
i) reacting 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl]methylpiperidine of Formula II,

Formula II
with source of hydrochloride to give crude hydrochloride salt of formula II,
ii) purifying the crude hydrochloride salt of formula II with alcoholic solvent to obtain pure hydrochloride salt of formula II and
iii) converting pure hydrochloride salt of formula II to highly pure donepezil hydrochloride.

Claim 7. The process as claimed in claim 6, wherein the source of hydrochloride used in step i) is methanolic-hydrochloride.

Claim 8. The process as claimed in claim 6, wherein the crude hydrochloride salt of formula II is purified by slurry washing the crude in alcohol solvent selected from methanol, ethanol, isopropanol and/or mixture at 35 °C to 55 °C for 30 minutes to 5 hours and then cool the reaction mixture at 5 °C to 25 °C to obtain pure hydrochloride salt of Formula II.
Claim 9. The process as claimed in claim 6, wherein the step iii) conversion is carried out by isolating pure hydrochloride salt of Formula II which is then basified and the resulting 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-ylidenyl] methyl piperidine of Formula II is conveted to highly pure donepezil hydrochloride of Formula I by the process as claimed in claim 1.
Claim 10. The highly pure donepezil hydrochloride of Formula I as prepared by the process of claim 1 or claim 2 is converted to highly pure donepezil free base.

Dated this 18th day of July 2022

Kapil
Manager-II, IPR
Ind-Swift Laboratories Limited