HYDROPHOBIC pH-SENSITIVE POLYAMINE GELS FOR LONG-TERM CONTROLLED RELEASE SYSTEMS

AIM　To investigate the factors which affect the application of hydrophobic pH-sensitive polyamine gels to long-term release systems. METHODS　9-Aminoacridine (9AA) was used as a model drug, and the amount of drug released from the 9AA loaded gels in buffers at different pH values was measured spectrophotometrically. RESULTS　The copolymer gel based on ethyl methacrylate (EMA) and diethylaminoethyl methacrylate (DEA), with just 10 mol% of DEA in the gel, a release period of more than 320 days in a citrate buffer of pH 5 was obtained, but nothing was released at pH≥6. CONCLUSION　The hydrophobic pH-sensitive gels are promising materials for developing a long-term controlled release system by adjusting the hydrophobic/hydrophilic composition of the gels.