In this research a novel drug polymer was prepared. The gelatin as a natural polymer has been used in the pharmaceutical and biomedical for the controlled release through grafted copolymerization with un saturated acid anhydride such as methyl nadic anhydride (Methyl-5-norbornene-2,3-dicarboxylic anhydride), formatted gelatin-g-methyl nadic anhydride copolymer A1, then modified to its corresponding polymer A2 by substituted amoxilline as useful derivative as biomaterial. The prepared drug biopolymer was characterization by FT-IR spectroscopy and controlled drug release was considered in different buffer solution at 37 °C as in vitro study and controlled drug release was compared at zero time and after many days, the methyl nadic anhydride which was used as a spacer between gelatin and amoxilline. It can provide functional groups which are pendant through backbone of polymer substituted with drug through amide groups lead to good sustain release rate for hydrolysis through amide attachment gradually for many days. This design of carries for controlled delivery of the therapeutic agent which could release the entrapped drug over an extended period and control the drug release was compared at zero time and after few days, indicated the rate of hydrolysis in basic medium is higher than acidic medium through hydrolysis of amide groups. It was observed that modified drug release with extended drug action via slow release, also this study gave a new drug polymer and in vivo performance was indicated that it will be talented for some bio active applications.