¹Cumhuriyet Üniversitesi, Eczacılık Fakültesi, Farmasötik Kimya Anabilim Dalı, Sivas 58140, Türkiye DOI : 10.12991/mpj.20151910458 Poly(maleic anhydride-co-styrene) (MAST), poly(maleic anhydride-co-vinyl acetate) (MAVA), poly(maleic anhydride-co-methyl methacrylate) (MAMMA), poly(maleic anhydride-co-allyl phenyl ether) (MAAFE) and poly(maleic anhydride-alt-acrylic acid) (MAAA) copolymers were synthesized by free radical chain polymerization reaction. Modification/derivatization of the copolymers with active pharmaceutical ingredients, in amine form (-NH2), was performed by the ring opening reaction. Structural characterization of the copolymers and the conjugated products was carried out by Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance (1H-NMR). The FTIR and 1H-NMR spectra, confirmed that pharmaceutically active agents were covalently bonded to the MAVA copolymer in a succesfull manner. Furthermore cytotoxicity on healthy fibroblast cell lines, antiproliferative activity on cancer cell lines and antibacterial activity on bacterial strains were also investigated in-vitro for synthesized conjugates. MAVA copolymer was also selected the most suitable carrier for modification/derivaritization process by comparing its affinity to the pharmaceutically active agents. Keywords : Copolymer modification, ring opening reaction, antiproliferative activity, antibacterial activity, structural characterization