In the present work, the hydroxyl groups of starch polymers bonds with bioactive material (Ketoprofen drug) by esterification process. (direct esterification and indirect esterification). The modified starch polymers are characterized by some spectroscopic methods such as FTIR ,UV, H1. NMR and C13.NMR. The degree of substitution (D.S) of the hydroxyl groups in starch molecule was determined in all cases. The hydrolysis of modified starch polymers is carried out in the heterogeneous phase in a buffer solution of pH (2.0 , 7.0 and 9.0 ) at various temperatures (25, 37, and 45 Co). The amounts of released Ketoprofen drugs were quantitatively determined by using calibration curve method. Biodegradation (in vitro degradation) of modification starch polymers is carried out by enzymatic cleavage (using lipase enzyme) at pH 2.0 and 37Co. The amounts of released ketoprofen were quantitatively determined by U.V visible spectrophotometry by using the usual calibration curve method. In general, it was found that the release in presence of enzyme was faster than in hydrolysis process..