SIS derivative as a novel delivery system for ibuprofen

Abstract

Ibuprofen is a commonly used analgesic due to its effectiveness, but its half-life is relatively short. Therefore, finding an appropriate delivery system is a significant challenge. In this study, we designed a new controlled release carrier for ibuprofen using a biocompatible poly(styrene-b-isoprene-b-styrene) triblock copolymer. For this purpose, the polyisoprene block was modified with 2-mercaptoethanol or ethanolamine to introduce hydroxyl groups. These linkers allowed the incorporation of the drug through a covalent bond. The modified copolymers were characterized using spectroscopic techniques, including 1H NMR, FTIR-ATR, and UV-Vis, which confirmed successful synthesis. The thermal method revealed that the new delivery system has a lower glass transition temperature than its precursor, verifying the incorporation of the hydrophobic drug. Furthermore, enzymatic release of ibuprofen was studied under physiological conditions and was found to be slow and sustained over time. The in vitro biocompatibility of the release system was evaluated using RAW264.7 monocytes. It was found that cells were able to adhere and proliferate onto the matrices. Additionally, the cells growing on ibuprofen-substituted SIS produced low levels of nitric oxide, a marker of cytotoxicity, when compared to cells growing on tissue culture plates. Taken together, the findings indicate that the polymer may serve as a promising delivery system for ibuprofen with potential biological applications.