Patent ID: 7521061

Claim:
A method for preparing a delayed-release formulation which comprises combining: a) a weight percentage of a biologically active compound having a chemical structure with hydrogen bonding sites, and b) a biocompatible, hydrolytically degradable polyarylate copolymer comprising tyrosine-derived diphenol monomer units with pendant carboxylic acid groups and tyrosine-derived diphenol monomer units with pendant carboxylic acid ester groups, said copolymer having a mole percentage of the monomer units with pendant carboxylic acid groups, to produce said formulation, wherein the weight percentage of the biologically active compound in the formulation relative to the mole percent of the monomer units with pendant carboxylic acid groups in the copolymer is effective to provide reproducible release profiles of the biologically active compound from the formulation under physiological conditions with a time lag inversely proportional to the mole percent of the monomer units with pendant carboxylic acid groups and without leaching the biologically active compound during the lag time.