Synthesis of Biocompatible Polymers with Aspirin-Moieties for Aspirin Delivery

ABSTRACT: Polyacrylate and polyhydroxylate polymers with aspirin moieties were prepared. The acrylate polymers were obtained by the synthesis and poly-merization of several new monomers; β-(acetylsalicylyloxy)ethy methacrylate, β-(acetylsalicylyloxy)propyl methacrylate, β-(acetylsalicylyloxy)ethy acrylate, β-hydroxy-γ-(acetylsalicylyloxy)ethyl methacrylate and β-hydroxy-γ-(acetylsali-cylyloxy)propyl methacrylate. The second series of biocompatible polymers with aspirin moieties was prepared by reacting the hydroxyl group of poly(vinyl alcohol) and poly(allyl alcohol) with 1-(acetylsalicylyl)benzotriazole. Both the homogeneous and heterogeneous hydrolysis of eight biocompatible polymers and copolymer with aspirin moieties were investigated in acidic or alkaline medium at 37 ° C or 60 °C, respectively. The main hydrolysis product was aspi-rin with minor amounts of salicylic acid. The release rates of aspirin and sali-cylic acid were related to the hydrolysis temperature, and the length of side chain. The release rate of aspirin and salicylic acid from poly[1-(acetylsalicylyl-oxy)ethyl methacrylate-co-methacrylic acid] is markedly dependent on polymer composition and the pH value of hydrolysis medium