fatty acid terminated polyanhydrides suitable for use as controlled release matrices in biodegradable sustained release drug delivery systems and methods for making thereof are described . the polymers are more soluble in organic solvents , and have a lower melting point than the corresponding non - fatty acid terminated polyanhydrides . the fatty acid terminated polyanhydrides are also more hydrophobic than the corresponding polyanhydrides that are not terminated with a fatty acid , and combine the properties of thermodynamic and hydrolytic stability , and easy storage . the polymers can be produced with a controlled and low molecular weight . the polyanhydrides are useful in a number of applications , including as a matrix in biodegradable drug delivery systems .