Preparation and Characterization of L-ascorbic Acid Ethosomal Formulation for Enhancement of Permeation

Abstract

Background: Vesicular system is a good approach to improve hydrophilic drug permeability using phospholipids as Nanocarriers to increase lipophilicity and reduce vesicle size. L-ascorbic acid is a water soluble vitamin with antioxidant activity with poor skin permeability. Aim: The purpose of this work is to prepare LAA-containing ethosomes formulations utilizing a modified thin film hydration approach. Methods: eight formulas were prepared using different types of phospholipids (egg yolk lecithin and soya lecithin), different volumes of ethanol (2 and 3mL), and tween 80 as a surfactant. The prepared formulas (F1, F2, F3, F4, F5, F6, F7 and F8) were characterized to detect the best one regarding the physical appearance, pH, average vesicle size, polydispersity index (PDI) and entrapment efficiency. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to evaluate the morphological properties Results: The best prepared ethosomal formula was F3 which contains (1.5g) LAA, (0.1 g) egg yolk lecithin, (2 mL) ethanol, 0.025 mL tween 80 and (q.s.10mL) of distilled water. Its average vesicle size value (176nm), PDI = 0.243, high entrapment efficiency (89.8%) and good physical stability. The morphological properties showing spherical, smooth, and devoid of drug crystalline structures.  The drug-excipient compatibility is confirmed using (FTIR, DSC and PXRD) analyses. Additionally, the Ex-vivo drug permeation investigation demonstrated that the prepared formula of LAA had flux and permeability coefficients that were two times higher than the control. Conclusions: The average vesicle size and PDI are affected by, the volume of ethanol, type of lecithin and presence of solubilizing agent.