Process for the preparation of microspheres made of a biodegradable polymeric material

Claim 1

A process for preparing a composition for the sustained and controlled release of a medicamentous peptide substance, said medicamentous peptide substance being a natural or synthetic poly peptide comprising from about 3 to about 45 amino acids, said composition being obtained in the form of microspheres of a biodegradable polymeric organic material incorporating said medicamentous substance, comprising the steps of: (a) converting a water soluble peptide or peptide salt into a corresponding water-insoluble peptide salt selected from the group consisting of the pamoate, stearate, and palmitate of said peptide; (b) suspending said water-insoluble peptide salt in an organic solvent containing a dissolved biodegradable polymeric organic material to form a suspension; (c) dispersing said organic suspension in an aqueous medium to form an aqueous emulsion, where the aqueous medium forms the continuous phase of the emulsion; (d) transferring said emulsion into an excess of an aqueous medium, and separating microspheres from the liquid phase.