a method for synthetizing polyanhydrides in solution using coupling agents and a removable acid acceptor to effect a one - step polymerization of dicarboxylic acids . as used in the method , these coupling agents include phosgene , diphosgene , and acid chlorides . insoluble acid acceptors include insoluble polyamines and crosslinked polyamines such as polyethyleneimine and polyvinylpyridine and inorganic bases such as k 2 co 3 , na 2 co 3 , nahco 3 , and caco 3 . the only byproduct formed is a removable hydrochloric acid - acid acceptor . examples are provided of the polymerization of highly pure polyanhydrides using phosgene , diphosgene or an acid chloride as the coupling agent , in combination with either an insoluble acid acceptor or a soluble acid acceptor in a solvent wherein the polymerizaiton byproduct or polymer is insoluble . a particularly important application of these polyanhydrides is in the formation of drug delivery devices containing bioactive compounds . the method is also useful in the polymerization of dicarboxylic acids including heat liable dipeptides of glutamic or aspartic acid .