Patent ID: 8927023
Filing Date: 2015-01-06
Classification: A61K,C08F

Abstract:
1. A process for preparation of a polymer of high purity and substantially free of respective toxic monomeric contaminants and containing respective toxic monomeric contaminants in amounts less than 0.001%, comprising the steps of: i) Dissolving N-isopropylacrylamide (NIPAM), 1-vinylpyrrolidone (VP), and ester of maleic anhydride and polyethylene glycol (MPEG) in water; ii) Adding in succession to the solution of step i), a cross-linking agent and an activator; iii) Bubbling an inert gas into the solution of step ii) for a period of between 30 to 60 minutes; iv) Adding an activator and a polymerization initiator to the solution of step iv); v) Polymerizing the solution of step iv), at a temperature of between 25° C. to 45° C., under an atmosphere of an inert gas for 3 to 6 hours; vi) Subjecting the solution of step v) to filtration through pre-sterilized filters and collecting the filtrate; vii) Subjecting the filtrate of step vi) to diafiltration and collecting the filtrate; viii) Optionally subjecting the filtrate of step vii) to an additional step of diafiltration and collecting the filtrate; and ix) Optionally subjecting the filtrate of step vii) or viii) to lyophilization to obtain a lyophilized powder of the polymer.