摘要 |
<p>Blends of polymers having properties distinct from the individual polymer components, and that are suitable for use as carriers of pharmaceutically active agents, are prepared from two or more polyanhydrides, polyesters or mixtures of polyanhydrides and polyesters. The blends have different properties than the polymers used to prepare the blends, providing a means for altering the characteristics of a polymeric matrix without altering the chemical structure of the component polymers. Blends of various polyanhydrides, polyesters, and polyanhydrides and polyesters, containing pharmaceutically active agents, are prepared using solvent mixing or melt mixing procedures. It has been discovered that the rate of release of the agent from the blends is different than the rate of release from the individual polyanhydride and polyester polymer components, being a function of the blend composition.</p> |