New topical microemulsions of etofenamate as sufficient management of osteoarthritis

Abstract In this study, microemulsions containing etofenamate were prepared and evaluated as dermal delivery carriers. The developed microemulsions consist of oleic acid, Span 80, Tween 20, Cremophor EL, Transcutol and ethanol. The percentage of etofenamate loading in the microemulsions was 5% (w/w). The characterization of formulations included droplet size, zeta potential, pH, conductivity, PDI, refractive index and viscosity. Moreover, ex vivo penetration study was carried out using mice abdominal skin. The developed formulations were analyzed for their cytotoxicity via MTT assay and tested for their anti-inflammatory properties opposed to LPS-stimulated nitrite prοduction in RAW 264.7 cells. As ideal formulation, M2ETF, was chosen due to its greater permeation, lower penetration as well as higher anti-inflammatory activity compared to other microemulsions.