A formulation comprising: a co-polyester comprising (a) the reaction product of a polycondensation polyester and (b) glycolide; wherein the polycondensation polyester comprises the reaction product of diglycolic acid and/or a derivative thereof and ethylene glycol, and the co-polyester comprises about 40% by weight of the polycondensation polyester based on the total weight of the co-polyester; and a drug selected from the group consisting of indomethacin, diclofenac sodium, and ketoprofen.