Abstract: There is disclosed a process for the extraction of volatile solvents entrained in a polymer-based pharmaceutical composition designed for sustained release of drug over an extended period of time prepared in microcapsule form wherein the composition comprises at least one hormonally active water-soluble polypeptide in an effective amount greater than a conventional single dose and a biocompatible, bioerodable encapsulating polymer, which process comprises the steps of contacting the composition to a stream of dense gas, that is, pressurized gas and then removing the dense gas, and volatile solvents contained therein, extracted from the pharmaceutical composition.