Process of preparing microcapsules of lactides or lactide copolymers with glycolides and/or .epsilon.-caprolactones

A process for preparing a microcapsule having an aqueous functional core material encapsulated in a PLA which comprises:

• (a) dissolving PLA in a mixture of two miscible organic liquids, the first being a liquid having solvent power for PLA and the second having little or no solvent power for PLA, the two liquids being present in a ratio such that the solution is near its saturation point for PLA, the liquid having solvent power for PLA having a vapor pressure significantly higher than the vapor pressure of the second liquid,
• (b) agitating the solution of step (a) and adding thereto an aqueous functional core material so as to uniformly disperse the aqueous functional core material as a fine suspension throughout the continuous liquid phase having the PLA dissolved therein, and
• (c) vaporizing the liquid having solvent power for PLA from the suspension of step (b) while continuing agitation so as to cause phase separation of the PLA and encapsulation of the finely dispersed aqueous functional core material with PLA, and
• (d) transferring the dispersion of step (c) into an agitated mass of an organic liquid having little or no solvent power for PLA to precipitate any remaining dissolved PLA and harden the PLA which has encapsulated the aqueous functional core material.