the present invention provides methods for purifying polymers . in each embodiment of the invention disclosed herein , a supercritical fluid is contacted with an organic solution that includes a polymer to be purified dissolved in an organic solvent . the supercritical fluid extracts the organic solvent from the organic solution . impurities such as residual monomers and process solvents are removed with the organic solvent and supercritical fluid , thereby purifying the polymer . the methods of the invention are particularly suitable for use in the purification of biodegradable polymers for use in pharmaceutical applications .