ABSTRACT
Many drugs of topical delivery suffer from poor penetration through skin because of their poor solubility. During the past decades, there has been wide interest in exploring new techniques to increase drug absorption through skin. Ethosomes which are novel permeation-enhancing lipid vesicles embodying high concentration (20–45%) of ethanol have the capability of carrying away the poorly soluble drugs into various layers of the skin. Hence, in this study, a model drug, diclofenac sodium, was used to study the effect of ethosomes on topical skin penetration. The compatibility of Phospholipon 90H and diclofenac sodium was studied using Fourier-transform infrared spectroscopy (FTIR) and was found with no incompatibilities. In vitro permeation studies were performed using 282Franz diffusion cell to compare the drug permeation and retention across pig skin, of ethosomal systems against hydroethanolic solution of drug and phospholipid and marketed Omnigel®. The ethosomal system showed the highest drug permeation (18.76%) after 12 h of study, more than 6% higher than that of the marketed formulation. The ehosomal system also showed the highest skin retention of diclofenac (3.62 μg/cm 2 ) compared to the hydroethanolic solution and the marketed product. This study confirms the use of ethosomes as a better therapeutic tool for the topical delivery of poorly permeable drugs.
