| abstract |
Polymers formed by incomplete esterification of the hydroxy groups of a water-soluble polymer such as polyvinyl alcohol, amylose or dextran with a pharmacologically acceptable mono-or di-carboxylic acid to an extent sufficient to render the polymer water-insoluble although still water-swellable, are biodegradable. They are useful for the formulation of pharmaceutical compositions for parenteral administration, particularly in the form of injectable fine particles in which a drug is intimately mixed with or encapsulated by the polymer. |