Ethosomal formulation composed of standardized Orthosiphon stamineus extract and sophorolipid inhibits angiogenesis of melanoma in vivo

Cancer disease involves the abnormal growth of cells that have the ability to invade other organs. Melanoma is one of the angiogenesis dependent cancer. Orthosiphon stamineus (EXOS) extract is a well-known antiangiogenic herb in South Asia. Thin-film hydration method has been employed to develop ethosome, a flexible liposomal gel formulation composed of standard extract of O.S leaves (SLOS) using sophorolipid (SL) and investigated its physicochemical properties for topical drug delivery system. High Performance Liquid Chromatography (HPLC) determined 76.02.02±1.2% entrapment of rosmarinic acid (RA) in ethosome vesicle. The average particle size of optimized vesicle was 189.9 nm with potential of -35.5 mV. SLOS at concentration of 1% demonstrated proper plastic flow, which could facilitate achieving effective and maximum skin permeation of EXOS. Permeation studies using albino mice revealed that the SLOS demonstrated higher penetrability through deeper layers of skin than the conventional hydroethanolic gel composed of EXOS. Cytotoxic test on normal endothelial cells confirmed the safety of SLOS formulation. In vivo melanoma tumor model study revealed that SLOS showed 97.07±0.6% anti -tumor activity during 16 days of study. These results revealed that SLOS vesicles can be considered for effective dermal therapeutic agent for the treatment of