| abstract |
Microparticles useful as DDS preparations are made by associating amphipathic polymers made of hydrophobic poly(hydroxy acid) segments and hydrophilic polysaccharide or polyethylene glycol segments having hydrophilic active substance-containing particles made by including a hydrophilic active substance that can efficiently seal in the hydrophilic active substance and that can release the hydrophilic active substance into the body at an appropriate rate. |