DESC:FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION:
“Process for preparation of polymer granules”

2. APPLICANT:
1. (A) Corel pharma chem
(B) Indian
(C) Corel House, Near Shayona Marble, Opp. Bhagwat Petrol Pump, Sarkhej-Gandhinagar Highway, Gota,
Ahmedabad-382481
Gujarat, India.

3. PREMABLE TO THE DESCRIPTION:
PROVISIONAL
SPECIFICATION
(See section 10 and rule 13)
The following specification describes the invention.
??COMPLETE
SPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION

The present invention relates to a process for preparation of polymer granules.

BACKGROUND OF INVENTION

Polyacrylic acid or PAA is a type of polymer. The monomer of polyacrylic acid is acrylic acid. Polyacrylic acid (PAA or Carbomer) is generic name for synthetic high molecular weight polymers of acrylic acid. Polyacrylic acid is homopolymers of acrylic acid, crosslinked with an allyl ether pentaerythritol, allyl ether of sucrose or allyl ether of propylene. In a water solution at neutral pH, polyacrylic acid is an anionic polymer, i.e. many of the side chains of polyacrylic acid will lose their protons and acquire a negative charge. This makes polyacrylic acids polyelectrolytes, with the ability to absorb and retain water and swell to many times their original volume.

Polyacrylic acids are also popular as thickening, dispersing, suspending and emulsifying agents in pharmaceuticals, cosmetics and paints. The neutralized polyacrylic acid gels are suitable to obtain biocompatible matrices for medical applications such as gels for skin care or skin disease treatment products.

Dry polyacrylic acids are found in the market as white and fluffy powders. Such powders often have poor flow characteristics and are resistant to blending and dispersion in liquids due to clumping and poor wetting. The dust associated with the powders can exhibit static charge effects. Additional problems include difficulty in handling and, difficulty in feeding through volumetric metering equipment. Many such powders have historically been granulated to vary their particle size distribution in order to improve their characteristics.

Polyacrylic acid resins which are to be used in applications involving swelling with aqueous electrolyte solutions. Polyacrylic acids are commonly polymerized in non aqueous polymerizations where the insoluble polymer can be isolated as powders. These powders comprised of aggregated or agglomerated polymer chains are significantly easier to disperse and dissolve in water than the bulk polymer. However, these polyacrylic acid powders have been noted for their static electricity charge, poor powder flow and some difficult in making dispersions in water since their introduction in 1958.

There are variety of methods which have been employed by powdered material suppliers and users in an attempt to reduce handling difficulties of powders. Slugging hot roll milling, and fluidized bed or wet agglomeration processes are well known processes for converting powders to granules.

One such patent US4386120A discloses a powder of polyacrylic acid salt is fluidized in the fluidized bed granulating device, an aqueous solution of polyacrylic acid salt is sprayed thereon to form granules and then the granules are dried. polyacrylic acid salt to be sprayed is preferably the same compound as the polyacrylic acid salt to be granulated. The limitation of this invention is the process is expensive and optimization of granulation needs extensive development work, fluidized bed systems may not provide adequate mixing of powder components. In fact there is a tendency for demising to occur when there are disparities in particle size or density in the materials being processed. Particles with granulating agent on their surface tend to stick to the equipment filters.

US 2011/0220745 disclose when fluidised bed method is not possible or difficult to handle, dry granulation is a valid alternative. A dry granulation process is described in the art as a method where the powders to be granulated are first mixed (if necessary) and then densified e.g. in the case of roll compaction by passing them between two rotating rolls. The ribbons or flakes resulting from such compaction are then broken into granules by passing the ribbons/flakes through a flake breaker and/or through a sieve granulator
US 2011/0220745 further disclose that lot of devices have been created in order to feed homogeneously the compaction rollers or other densifcation devices, to avoid the formation of dust in the sieve granulator, to control the compaction force, in order to have an uniform ribbon, and to avoid an over compaction (which can have a bad influence also on the dissolution rate of the tablets) etc. Nevertheless, as result of a normal dry granulation (for instance roll compaction), the produced granulated bulk is not generally homogeneous, because of the contemporary presence in it of big (1 -2 mm of diameter) depending on the size of the sieve openings in the sieve granulator) and sometimes dense granules together with very small (a few micrometers of diameter) light particles. This fact, which is mostly a natural consequence of the fake breaking and/or granulating process, causes a bad flowability of the material and segregation (i.e. the more dense granules flow faster than the less dense) with the result of rejecting complete batches, because of the bad uniformity content of the granules or recycling it.
Hence, to overcome the above mention problems, it is desperately needed to invent a process for preparation of polyacrylic acid crosslinked granules which is not subjected to above mention problems.

OBJECT OF THE INVENTION
The main object of the present invention is to provide process for preparation of polymer in required granule size.

Another object of the present invention is to provide process for preparation of polymer granules with low amount of dusting compared to powder form of polyacrylic acid to granules.
Further object of the present invention is to provide polymer granules which are used in sustained release formulation to achieve various release profile As well as dust free polyacrylic acid used in other industrial use.
Another object of the present invention is to provide polyacrylic acid cross linked granules with excellent self life compared to powder form of polyacrylic acid.

Further object of the present invention is to provide polymer granules which are used alone or in combination with other extended release excipients to improve flow properties of the formulations.

Still another object of the present invention is to provide polymer granules which are used alone or in combination with other extended release excipients to improve direct compression properties of the formulations.

SUMMARY OF THE INVENTION

The present invention provides process for preparation of polymer granules comprises solvent are taken into closed reaction vessel with high speed stirrer and nitrogen bubbled is charged. Acrylic acid, coagulating agent, cross linking agent are mixed in another vessel. 20-40 % of above prepared mixture is mixed with catalyst and pours it into first vessel. Solvent and catalyst are mixed separately and added into remaining 60-80 % of second vessel. Remaining mixture of solvent and catalyst are added into first vessel slowly in 30 minutes. The reaction mixture is polymerized till 2-4 hours cooled and dried. The granules are determine which are used for sustained release formulation as suspending agent for oral liquid, as direct compression formulation and to achieve various release profile. The present invention provides process for preparation of polymer granules which is rapid, time saving, easy, economical, gives product with less or no impurities and improve flow properties.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 illustrates the image of granular form of the sample polymer granules.
Fig. 2 illustrates release pattern of ascorbic acid 500 mg tablet in which the sample polymer granules is used.
Fig. 3 illustrates release pattern of ascorbic acid 500 mg tablet in which the standard polymer granules made by lubrizol is used.

DETAIL DESCRIPTION OF THE INVENTION

The nature of invention and the manner in which it is performed is clearly described in the specification. The invention has various components and they are clearly described in the following pages of the complete specification.

The term polyacrylic acid is used to include various homopolymers and copolymers wherein at least 50 or 75 mole percent of the repeating units have carboxylic acid groups or anhydrides of carboxylic acid groups. While acrylic acid is the most common primary monomer used to form polyacrylic acid the term is not limited thereto but includes generally all a-ß unsaturated monomer with carboxylic group.

Poly (acrylic acid) or PAA is a type of polymer. The monomer of poly (acrylic acid) is acrylic acid. In a water solution at neutral pH, many of the side chains of PAA will lose their protons and acquire a negative charge. Polyacrylic acid is a large-molecular-weight compound called a polymer, which consists of small repeating units called monomers.

Acrylic acid abbreviated as AA, (IUPAC: prop-2-enoic acid) is an organic compound with the formula CH2=CHCO2H. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This is colorless liquid which has a characteristic acrid or tart smell. It is miscible with water, alcohols, ethers, and chloroform.

Acidic vinyl monomers or a, ß-ethylenically unsaturated carboxylic acid monomers suitable for use in the present invention are acidic, polymerizable, ethylenically unsaturated monomers preferably containing at least one carboxylic acid, sulfonic acid group, or a phosphoric acid group to provide an acidic or anionic functional site. These acid groups can be derived from monoacids or diacids, anhydrides of dicarboxylic acids, monoesters of diacids, and salts thereof. Suitable acidic vinyl carboxylic acid-containing monomers include, but are not limited to: acrylic acid, methacrylic acid, itaconic acid, citraconic acid, maleic acid, fumaric acid, crotonic acid, aconitic acid, and the like, and Cl-Cl8 alkyl monoesters of maleic, fumaric, itaconic, or aconitic acid, such as methyl hydrogen maleate, mono isopropyl maleate, butyl hydrogen fumarate, and the like.

Crosslink is a bond that links one polymer chain to another. They can be covalent bonds or ionic bonds. Polymer chains can refer to synthetic polymers or natural polymers (such as proteins). When polymer chains are linked together by crosslinks, they lose some of their ability to move as individual polymer chains. For example a liquid polymer can be turned into a solid or gel by crosslinking the chains together.

In the present invention, the process for preparation of polymer granules obtained by direct polymerizing process. In such process the closed reaction vessel with high speed stirrer and 30-40 minute nitrogen bubbled is charged with solvent, acrylic acid, crosslinking agent and coagulating agent are polymerized, centrifuged and dried. The granules are found which is used as sustained release formulation, to prepared gels of diluted and neutralized polymer.

The formulas for preparation of polymer granules is developed through various trials to get enhance flow ability and minimum impurities.

The process for preparation of polymer granules comprises following steps:

i) In the closed reaction vessel with high speed stirrer and 30-40 minutes nitrogen bubbled charged with solvent and maintained 65-75° C temperature.
ii) In another vessel, acrylic acid, coagulating agent and cross linking agent are taken and prepare reaction mixture.
iii) Catalyst is mixed with 20-40 % of above prepared reaction mixture then pours it in step (i) at 65-75° C.
iv) Solvent and catalyst are mixed separately and added into remaining 60-80 % of prepared reaction mixture in step (ii).
v) The prepared reaction mixture from step (iv) is added into step (i) slowly in 30 minutes.
vi) The reaction mixture is polymerized for 2 to 4 hours and cooled it at room temperature.
vii) The granules are separated and dried in dryer.
viii) Final product is collected and stored.

Acrylic Acid derivatives are selected from the group consisting of: acrylic acid, bromo acrylic acid, bromo methyl acrylic acid, ethylacrylic acid, carboxyethyl acrylate, propylacrylic acid, fluoromethylacrylic acid, benzoylhydroxyphenoxyethyl acrylate, benzylpropylacrylate, butyl acrylate butyl aminocarbonyl oxyethy acrylate, butyl bromoacrylate, butylcyclohexyl acrylate, carboxyethyl acrylate, chloroethyl acrylate, diethylamino ethyl acrylate, ethylene glycol ethyl ether acrylate, ethylene glycol ethylhexyl ether acrylate, dimethylamino ethyl acrylate, dimethylamino propyl acrylate, ethyl acrylate, bromomethy acrylate, cyano acrylate, ethylene glycol dicyclopentenyl ether acrylate, ethylene glycol methyl ether acrylate, ethylene glycol phenyl ether acrylate, ethyl ethylacrylate, ethyl hexyl acrylate, ethyl propylacrylate, ethyl trimethylsilylmethyl acrylate, hexyl acrylate, hydroxybutyl acrylate, hydroxyethyl acrylate, hydroxy phenoxypropyl acrylate, hydroxypropyl acrylate, bornyl acrylate, butyl acrylate, decyl acrylate, octyl acrylate, lauryl acrylate, methacrylic acid, methyl acetamidoacrylate, methyl acrylate, methyl bromoacrylate, methyl bromomethylacrylate, methyl chloromethyl acrylate, methyl hydroxy methylenebutyrate, methyl fluoromethyl acrylate, octadecyl acrylate, pentabromobenzyl acrylate, pentabromophenyl acrylate, pentafluorophenyl acrylate, polyethyleneglycol acrylate, polyethyleneglycol diacrylate, polyethyleneglycol methyl ether acrylate, polypropyleneglycol acrylate,tetrahydrofurfuryl acrylate, tetrahydropyranyl acrylate, trimethoxysilyl propyl acrylate, trimethylhexyl acrylate and undecenyl acrylate.

Crosslinking agent includes divinylbenzene, divinyl toluenes, divinylnaphthalenes, diallyl phthalate, ethyleneglycoldiacrylate, ethyleneglycoldimethacrylate, trimethylolpropane trimethacrylate, neopentyl glycol dimethacrylate, bis-phenol dimethacrylate, pentaerythrital, tetra and trimethacrylates, divinylxylene, divinylethylbenzene, divinylsulfone, divinylketone, divinylsulfide, allyl acrylate, diallyl maleate, diallyl fumarate, diallyl succinate, diallyl carbonate, diallyl malonate, diallyl oxalate, diallyl adipate, diallyl sebacate, divinyl sebacate, diallyl tartrate, diallyl silicate, triallyl tricarballylate, triallyl aconitate, triallyl citrate, triallyl phosphate, N,N'-methylenediacrylamide, N,N'-methylene dimethacrylamide, N,N'-ethylenediacrylamide, trivinylbenzene, trivinylnaphthalene, polyvinylanthracenes andthe polylallyl and polyvinyl ethers of glycolglycerol, pentaerythritol, resorcinol and the monothio- or dithio-derivatives of glycols. More preferably trimethylolpropane trimethacrylate is used as polyunsaturated monomer.

Solvent of the present invention is selected but not limited to benzene, hexane, cyclohexane and ethyl acetate ethylene dichloride and methylene di chloride. More preferably ethyl acetate is used as solvent.

The co-polymerization is accelerated by means of well recognized azo catalysts including ozone, ozonides, organic periodic compounds such as acetyl peroxide, laurayl peroxide, stearoyl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, di-tert butylperoxide (2, 2'-azobisisobutyronitrile) 1,1’-Azobiscyclohexanecarbonitrile, 2,2'-Azobis(2,4-dimethylvaleronitrile) or 2,2'-azobis(2,4-dimethylpentanenitrile) or 2-(2-Cyano-4-methylpentan-2-yl)diazenyl-2,4-dimethylpentanenitrile, 2,2'-azobis(2-methylpropanenitrile) or 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutanenitrile) or 2,2'-azobis(methylbutyronitrile) are used separately or in combination as catalyst.

Coagulating agents of the present invention are selected but not limited to herbsol, copovidone, hypermellose, polyethylene glycols, polyprpylene glycol, isomalt, maititol, polydextrose, and sucrose. More preferably polyethylene glycol 400, 600 or combination is used as coagulating agent.

In above process 9.50 % to 15.80 % acrylic acid, 0.0030 % to 0.70 % coagulating agent, 0.12 % to 0.25 % crosslinking agent, 0.00001 % to 0.0040 % catalyst (for step (iii)) is used. Further, 60 % to 90 % solvent (for step (i)), 5 % to 25 % solvent (for step (iv)) and 0.00002 % to 0.0075 % catalyst (for step (iv)) are used.

For the optional process step, 4 % to 25 % solvent and 0.0052 % to 0.015 % benzoyl peroxide are used.

The invention is illustrated more in detail in the following example. The example describes and demonstrates embodiment within the scope of the present invention. This example is given solely for the purpose of illustration and is not to be construed as limitations of the present invention, as many variations thereof are possible without departing from the spirit and scope.

Example 1:

i) In the closed reaction vessel with high speed stirrer and 30-40 minutes nitrogen bubbled charged with 64 % ethyl acetate and maintained 65-75° C temperature.
ii) In another vessel 10.8 % acrylic acid, 0.59 % polyethylene glycol 400 and 0.14 % trimethyllolpropane triacryliate were taken and prepare reaction mixture.
iii) 0.00001 % di-tert butylperoxide (2, 2'-azobisisobutyronitrile) or 1,1’-Azobiscyclohexanecarbonitrile or 2,2'-Azobis(2,4-dimethylvaleronitrile) was mixed with 20-40 % of above prepared reaction mixture then pour it in step (i) at 65-75° C.
iv) 24.44 % ethyl acetate and 0.00002 % benzoyl peroxide were mixed separately and added into remaining 60-80 % of prepared reaction mixture in step (ii).
v) The prepared reaction mixture from step (iv) was added into step (i) slowly in 30 minutes.
vi) The reaction mixture was polymerized for 2 to 4 hours and cooled it at room temperature.
vii) The granules are separated and dried in dryer.
viii) Final product is collected and stored.

Results: The above prepared granules were as per required size.

Example 2:

i) In the closed reaction vessel with high speed stirrer and 30-40 minutes nitrogen bubbled charged with 74.12 % ethyl acetate and maintained 65-75° C temperature.
ii) In another vessel 13.01 % acrylic acid, 0.34 % polyethylene glycol 600 and 0.17 % trimethyllolpropane triacryliate were taken and prepare reaction mixture.
iii) 0.0013 % di-tert butylperoxide (2, 2'-azobisisobutyronitrile) or 1,1’-Azobiscyclohexanecarbonitrile or 2,2'-Azobis(2,4-dimethylvaleronitrile) was mixed with 20-40 % of above prepared reaction mixture then pour it in step (i) at 65-75° C.
iv) 12.33 % ethyl acetate and 0.0024 % benzoyl peroxide were mixed separately and added into remaining 60-80 % of prepared reaction mixture in step (ii).
v) The prepared reaction mixture from step (iv) was added into step (i) slowly in 30 minutes.
vi) The reaction mixture was polymerized for 2 to 4 hours and cooled it at room temperature.
vii) The granules are separated and dried in dryer.
viii) Final product is collected and stored.

Results: The above prepared granules were as per required size.

Example 3:

i) In the closed reaction vessel with high speed stirrer and 30-40 minutes nitrogen bubbled charged with 74.12 % ethyl acetate and maintained 65-75° C temperature.
ii) In another vessel 13.01 % acrylic acid, 0.17 % polyethylene glycol 400 and 0.17 % trimethyllolpropane triacryliate were taken and prepare reaction mixture.
iii) 0.0013 % di-tert butylperoxide (2, 2'-azobisisobutyronitrile) or 1,1’-Azobiscyclohexanecarbonitrile or 2,2'-Azobis(2,4-dimethylvaleronitrile) was mixed with 20-40 % of above prepared reaction mixture then pour it in step (i) at 65-75° C.
iv) 12.33 % ethyl acetate and 0.0024 % benzoyl peroxide were mixed separately and added into remaining 60-80 % of prepared reaction mixture in step (ii).
v) The prepared reaction mixture from step (iv) was added into step (i) slowly in 30 minutes.
vi) The reaction mixture was polymerized for 2 to 4 hours and cooled it at room temperature.
vii) The granules are separated and dried in dryer.
viii) Final product is collected and stored.

Result: The above prepared granules were as per required size

Example 4:

i) In the closed reaction vessel with high speed stirrer and 30-40 minutes nitrogen bubbled charged with 63.84 % ethyl acetate and maintained 65-75° C temperature.
ii) In another vessel 10.6 % acrylic acid, 0.59 % polyethylene glycol 600 and 0.14 % trimethyllolpropane triacryliate were taken and prepare reaction mixture.
iii) 0.0011 % di-tert butylperoxide (2, 2'-azobisisobutyronitrile) or 1,1’-Azobiscyclohexanecarbonitrile or 2,2'-Azobis(2,4-dimethylvaleronitrile) was mixed with 20-40 % of above prepared reaction mixture then pour it in step (i) at 65-75° C.
iv) 24.44 % ethyl acetate and 0.0023 % benzoyl peroxide were mixed separately and added into remaining 60-80 % of prepared reaction mixture in step (ii).
v) The prepared reaction mixture from step (iv) was added into step (i) slowly in 30 minutes.
vi) The reaction mixture was polymerized for 2 to 4 hours and cooled it at room temperature.
vii) The granules are separated and dried in dryer.
viii) Final product is collected and stored.

Results:
The above prepared granules were as per required size.

Evaluation studies of granules:
The final product was evaluated through various parameters. The final product i.e. polymer granules were used as sample of present invention. Characterization of granules is measured by the different parameters for evaluation studies are as follows:

Typical physical properties:
Parameter Typical Properties
Appearance White free flowing granules
Odor Mildly acidic
Brookfield Viscosity (25ºC, 0.5%
aqueous gel neutralized) 1,00 -11,000,0 mPa•s.
pH 1 wt% dispersion 2.5 -3.0
pKa 6.0 ± 0.5
Carboxylic acid content Between 56.0 % to 68.0%
Loss on drying NMT 2.0 %
Temperature Stability Upto 75ºC

1) Description:

Present invention was synthetic high molecular weight crosslinked polyacrylate polymer. Present invention was designed for use in oral solid dosage applications. Present invention was free-flowing granular form for use in direct compression formulations. The granules were free flowable, have increased bulk density, and contain minimal amounts of very small particles that causes dusting and/or static adherence compared to the powder polymer.

2) Viscosity measurement:
Granules made by the present process was taken and pulverized, after that water was added into it and prepared a gel, neutralized with NaOH. Maintained the pH upto 7.2 to 7.3 and checked the viscosity from Ostwald viscometer from spindle no. 4 at 20 rpm.

3) Flow property:
Method:
i) The Sample was evaluated for angle of repose, loose bulk density (LBD), tapped bulk density (TBD), compressibility index and Hausner Ratio.
ii) Angle of repose was determined by funnel method.
iii) Bulk density and tapped density were determined by cylinder method.
iv) Carr's index (CI) was calculated using the following equation.

Hausner's ratio was related to interparticle friction and could be used to predict powder flow properties. It was determined by following equation:

Results:
Parameter Present invention

Angel of repose (?) 28.723
Bulk Density gm/ml 0.472
Tapped density gm/ml 0.581
Hausner Ratio 1.10
Compressibility Index % 10.80

4) Comparison study:
The final product i.e. polyacrylic acid crosslinked granules was used as sample of present invention and Carbopol® 71G was used as a standard throughout the evaluation study. Carbopol® 71G is one of the marketed polyacrylic acids crosslinked granules of lubrizol.

For compression study sample polymer (present invention) & Acrypol 971P (powder form) and standard (Carbopol® 71G) & Carbopol® 971P (powder polymer) were included.

Preparation Methods:
Ascorbic acid 500 mg extended release tablets were manufactured by direct compression using sample polymer as matrix-forming excipients.

Ascorbic acid 500 mg extended release tablets were manufactured by direct compression using standard polymer as matrix-forming excipients.

To study the release behavior of Ascorbic acid, tablets were prepared in combination with i.e. 5 % Acrypol 971P + 20 % of present invention and 5 % Carbopol® 71G + 20 % Carbopol® 971P.

Result:
The formulation of sample polymer (5 % Acrypol 971P + 20 % of present invention), active release was extended for 10-12 hours.

The formulation of standard polymer (5 % Carbopol® 71G + 20 % Carbopol® 971P), active release was extended for 8-10 hours which was slower than the sample polymer.

Storage and handling:
Store in a tightly closed container and away from direct contact with water and excessive humidity condition.

Shelf life:
Five years from the date of manufacturing in intact condition.
,CLAIMS:We claim:

1. A process for preparation of polymer granules comprises following steps:
i) taking solvent in the close reaction vessel with high speed stirrer and charging with 30-40 minutes nitrogen bubble with maintaining the temperature at 65-75° C;
ii) taking acrylic acid, coagulating agent and cross linking agent in another reaction vessel and mixing it properly;
iii) mixing 20-40 % of above preparing reaction mixture with catalyst and pouring it in step (i) at 65-75° C;
iv) mixing solvent and catalyst separately and adding into remaining 60-80 % of above preparing reaction mixture in step (ii);
v) adding the above preparing reaction mixture from step (iv) into step (i) slowly in 30 minutes;
vi) polymerizing the reaction mixture for 2-4 hours and at room temperature;
vii) separating and drying the granular mixture.

2. The process for preparation of polymer granules as claimed in claim 1, wherein said acrylic acid is in an amount of 9.50 % to 15.80 %.

3. The process for preparation of polymer granules as claimed in claim 1, wherein said coagulating agent is in an amount of 0.0030 % to 0.70 %.

4. The process for preparation of polymer granules as claimed in claim 1, wherein said crosslinking agent is in an amount of 0.12 % to 0.25 %.

5. The process for preparation of polymer granules as claimed in claim 1 step (iii), wherein said catalyst is in an amount of 0.00001 % to 0.0040 %.

6. The process for preparation of polymer granules as claimed in claim 1 step (iv), wherein said catalyst is in an amount of 0.00002 % to 0.0075 %.

7. The process for preparation of polymer granules as claimed in claim 1 step (i), wherein said solvent is in an amount of 60 % to 90 %.

8. The process for preparation of polymer granules as claimed in claim 1 step (iv), wherein said solvent is in an amount of 5 % to 25 %.

9. The process for preparation of polymer granules as claimed in claim 1, wherein crosslinking agent is divinylbenzene, divinyl toluenes, divinylnaphthalenes, diallyl phthalate, ethyleneglycoldiacrylate, ethyleneglycoldimethacrylate, trimethylolpropane trimethacrylate, neopentyl glycol dimethacrylate, bis-phenol dimethacrylate, pentaerythrital, tetra and trimethacrylates, divinylxylene, divinylethylbenzene, divinylsulfone, divinylketone, divinylsulfide, allyl acrylate, diallyl maleate, diallyl fumarate, diallyl succinate, diallyl carbonate, diallyl malonate, diallyl oxalate, diallyl adipate, diallyl sebacate, divinyl sebacate, diallyl tartrate, diallyl silicate, triallyl tricarballylate, triallyl aconitate, triallyl citrate, triallyl phosphate, N,N'-methylenediacrylamide, N,N'-methylene dimethacrylamide, N,N'-ethylenediacrylamide, trivinylbenzene, trivinylnaphthalene, polyvinylanthracenes andthe polylallyl and polyvinyl ethers of glycolglycerol, pentaerythritol, resorcinol and the monothio- or dithio-derivatives of glycols.

10. The process for preparation of polymer granules as claimed in claim 1, wherein said coagulating agent is selected from herbsol, copovidone, hypermellose, polyethylene glycols.

11. The process for preparation of polymer granules as claimed in claim 1, wherein said solvent is selected from benzene, hexane, cyclohexane, ethyl acetate, ethylene dichloride, methylene dichloride etc.

Dated this on November 7, 2017