SYNTHESIS OF NOVEL HYDROLYTICALLY DEGRADABLE HYDROGELS FOR CONTROLLEDDRUG-RELEASE

This paper describes synthesis of hydrolytically degradable gels based on N-(2-hydroxypropyl)-methacrylamide copolymers with high potential for use in the synthesis of new drug release systems. The first part d eals with a study of the dependence between conditions of crosslinking copolymerization, the course of copolymerization and final properties of hydrogels thus formed. The second part is devoted to the study of hydrolytic degradation of hydrogels and in vitro studies of doxorubici n and polymer-doxorubicin conjugate release from hydrogel matrix. We h ave shown that the hydrogels under study were stable under acidic cond itions (in buffers at pH 5 and lower) and hydrolytically degradable at physiological pH (7.4). Both drug forms, free doxorubicin and its con jugate with water-soluble polymeric drug carrier, can be released from the hydrogel matrix at a rate depending on the rate of drug diffusion from the hydrogel, or the rate of hydrogel degradation, or at a rate controlled by a combination of both processes. In all cases the hydrog el matrix was degraded and a hydrophilic water-soluble polymeric produ ct was formed. Biological evaluation of drug-hydrogel systems describe d in this paper is under way.