Modeled in vivo release profiles for 50:50, 65:35, 75:25 and 85:15 poly lactic-co-glycolic acid. Notation 65:35 PLGA means 65% of the copolymer is lactic acid and 35% is glycolic acid. A biphasic release profile with a initial zero release period followed by a rapid drug release has been observed. The profiles also show increase in release rate with decrease in lactide to glycolide proportion.