Preparation of biodegradable microcapsules based on serum albumin

Claim 1

Process for preparing microcapsules containing a pharmaceutically active substance, wherein the mcrocapsules are prepared from serum albumin by carrying out the following successive operations: (a) the serum albumin is emulsified by dispersion in an organic solvent system, by adding a pharmaceutically acceptable emulsifying agent, and stirring; (b) to the emulsion thereby obtained, maintained stirred, a crosslinking agent dissolved in the said organic solvent system is added, and stirring is maintained until the desired degree of interfacial crosslinking is obtained; (c) the microcapsules are isolated after dilution of the reaction mixture followed by a succession of stages of washing with suitable solvents and decantation stages, and the microcapsules are then subjected to several washes with alcohol and to immersion in alcohol, preferably absolute, for at least 12 hours in order to denature the non-crosslinked serum albumin, and (d) after the microcapsules are dried, the pharmaceutically active substance is incorporated therein by controlled immersion of the microcapsules in a titrated solution of the said substrate.