Formulation and evaluation of detarium oil based organogel for sustained release of metronidazole via topical delivery

The rationale for this study was to increase the absorption of model drug metronidazole by formulating an organogel using detarium oil in place of conventional oils used in drug formulation such as liquid paraffin. The organogels were prepared by fluid-filled mechanism using metronidazole as the model drug. The drug-surfactant mixtures were dissolved in oil followed by the addition of water which led to the formation of organogels at specific compositions. The formulations were analyzed by microscopy, rheology, in vitro drug release and X-ray diffraction (XRD). Microscopic studies revealed the gels contained clusters of water-filled spherical structures. FTIR study showed compatibility of components of the organogels. DSC result showed all the organogels released heat during formation. The viscosity of the organogels showed an elastic flow followed by a non-elastic phase. The cumulative percentage release of metronidazole was found to be between 63% and 85% at the end of 10 h, with OGM 9 having the highest release. XRD result indicated the crystalline nature of the organogels. Metronidazole release from the organogels indicated dissolution, shape, size, and surface area dependent release. The results also showed good compatibility of all the excipients. Sustained release metronidazole organogel was successfully developed using detarium oil.