Controlled drug release studies of valsartan using differently sulfonated methacryloxyacetophenone and methyl methacrylate co-polymer resins as drug carriers.

ABSTRACT

2-methacryloxyacetophenone (MAP) was prepared and subjected to suspension polymerization with methyl methacrylate (MMA) using benzoylperoxide (BPO) as free radical initiator. The differently sulfonated MAPMMA cross-linked copolymer cationic exchange resins were prepared by sulfonation with concentrated sulphuric acid at 70oC. Several characteristics of the prepared resins were evaluated, i.e. FT-IR, the Ion-exchange capacity (IEC), Swelling studies, Particle size distribution and Microscopic morphology. The resin characteristics were altered with degree of sulfonation, providing that differently sulfonated resins could be prepared. The behavior of valsartan (VLN) loading and in vitro release in the USP stimulated gastric and intestinal fluids of the obtained resins were evaluated. The drug loaded in the resin increased with increasing degree of sulfonic group and hence the drug binding site in resin employed. The drug release was lower from the resins with higher degree of sulfonic group due to the increase in the diffusive path depth. The drug release was a little lower in stimulated gastric fluid (SGF) than stimulated intestinal fluids (SIF). The basic group, ionized to a little greater extent in SGF and preferred binding with the resin rather than releasing. Hence, the differently sulfonated resins could be utilized as novel carriers for drug delivery.