Process for the production of morphologically uniform microcapsules that consist of biodegradable polymers or copolymers, which contain peptides, proteins or other water-soluble, biologically active substances as active ingredients, characterized in that
- Polyesters of hydroxycarboxylic acids or block copolymers that consist of polyesters of hydroxycarboxylic acids and polyethylene glycol are dissolved in a halogen-free solvent or solvent mixture that is not water-miscible or is partially water-miscible,
- the buffered active ingredient solution, which has a pH of between 6.0 to 8.0, is dispersed into this solution,
- an aqueous solution that contains a surfactant or a mixture of surfactants is then added to this W/O-emulsion, and
- finally, the solvent or solvent mixture is removed in the usual way.