Patent ID: 7691412
Filing Date: 2010-04-06
Classification: A61K

Abstract:
1. A method for preparing a pharmaceutical composition in the form of microspheres with prolonged release of a water-soluble active principle, which comprises the succession of steps below: dissolving the active principle in an appropriate amount of water, emulsifying the aqueous solution of active principle thus obtained with a solution of a d,l-lactide-co-glycolide matrix copolymer of average molecular weight of between 40,000 and 80,000 and having a lactic acid/glycolic acid proportion of between 50/50 and 80/20, dissolved in a chlorinated hydrocarbon, in the absence of a release-modulating agent, resulting in a first microfine and homogeneous emulsion, wherein the d,l-lactide-co-glycolide matrix copolymer is present at a concentration of between 5 and 50% by weight relative to the total weight of the solution consisting of the copolymer dissolved in the chlorinated hydrocarbon, emulsifying said first emulsion thus obtained, in an external aqueous phase containing a surfactant, a viscosity-increasing agent and an osmotic agent, extracting-evaporating the solvent so as to obtain microspheres, which are recovered after filtration, washing and drying; the resultant microspheres exhibiting continuous release of active principle over a period of time of more than two months.