ASYMMETRIC MICROPOROUS BEADS FOR CONTROLLED RELEASE

摘要

ASYMMETRIC MICROPOROUS BEADS FOR CONTROLLED RELEASE A controlled release device is disclosed, the device comprising active ingredient in the pores of a polymeric microporous bead having an anisotropic pore structure of large pores in the interior and small pores at the surface, the gradation of pore sizes between the interior and the surface being continuous.