Development of mustard oil- and groundnut oil-based span 40 organogels as matrices for controlled drug delivery

The present study deals with the development and characterization of sorbitan monopalmitate (SM) organogels using mustard oil (MO) and groundnut oil (GO) as the apolar phase. In both the cases, the organogels containing ≥ 20% (w/w) SM were found to be stable for prolonged period. The microscopic studies showed the presence of aggregates of tubular shaped gelator fibers in the gel architecture. Fourier transform infrared spectroscopy indicated formation of intermolecular hydrogen bonding amongst the oil and gelator molecules. Differential scanning colorimetry studies indicated that the thermal stability of GO organogels was found to be more than the MO organogels. Gels showed pseudoplastic flow, with shear thinning and thixotropic behavior. The drug release from the organogels followed Higuchian kinetics with non-Fickian diffusion. The pH values of organogels were found to be near the human skin pH and highly hemocompatible. Metronidazole loaded organogels have shown good antimicrobial activity against Bacillus subtilis. Based on the preliminary studies, the developed organogels may be tried as drug carriers.