DEVELOPMENT AND EVALUATION OF NATURAL RUBBER MEMBRANES FOR SUSTAINED TRANSDERMAL DRUG RELEASE APPLICATIONS

Abstract

The improvement in the style of drug release and increase in the demand for biomaterials that continuously release substances of pharmacological interest is on the increase in medicinal chemistry. Natural rubber is a polymeric material that is readily available with an exceptional matrix-forming feature which makes it suitable for controlling drug delivery system. Natural rubber latex was obtained from the rubber tree, Hevea brasiliensis, with exceptional matrix forming features needed for this research. This study developed an exceptional matrix-forming feature and sustainable system of delivery of phytochemicals with natural rubber latex matrix serving as the base for the transdermal patches. Natural rubber latex was centrifuged at 8000 rpm to remove the leachable protein. The modified natural rubber latex and phytochemicals were polymerized at –10, 15, 35, 50 °C. The biomembrane was characterised using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), Ultraviolet-Visible Spectroscopy and ImageJ. From the results of the size distribution, the number of pores in the biomembranes and the overall morphology of the biomembranes depend on the temperature of polymerisation. Results confirmed that the polymerized biomembrane at –10°C was the best system for drug-delivery for phytochemicals. The bioactive compound (phytochemicals) and matrix did not interact chemically as revealed by FTIR analysis. Only 32% of all integrated extracts were released within 72 hours in the biomembrane for the phytochemical. The average pore sizes also decreased as the temperature of polymerization increased. ImageJ analysis revealed that the average pores of phytochemical biomembranes polymerized at -10, 15, 35, and 50 oC were 4.54, 3.24, 1.23 and 0.58 μm respectively. The images from the SEM showed a bioactive portion on the surface of the matrix, which was responsible for the fast release. Similarly, some bioactive portions were observed in the matrix which was the cause of the slow release. The antioxidant activities of the bioactive substances were sustained even when they have been integrated into the matrix. The results confirmed that the biomembranes produced have shown effectiveness as a model in the release of bioactive compounds (phytochemicals) for transdermal purposes.