Abstract

Abhiram Sahu*, Srimanta Kumar Das, Ranjan Kumar Sahoo, Ashutosh Meher

ABSTRACT

Ethosomes are advanced, highly flexible lipid-based vesicular delivery systems made of phospholipids, water and high concentrations of alcohol (20-45% ethanol or isopropyl alcohol). The skin is made up of three primary layers, the epidermis, dermis and hypodermis. The epidermis is made up of 40-50 layers of stacked squamous epithelial cells in the stratum basale, stratum spinosum, stratum granulosum and stratum corneum. Conventional liposomes have limitations in deep delivery, while ethosomes can be used as “push and pull” devices to improve transdermal penetration and intracellular distribution of high molecular weight compounds into these deep epidermal layers. This review aims to provide insight into the classification, preparation techniques, mechanisms of ethosomes and to assess their potential for optimising the transdermal delivery of bioactive herbal extracts. Ethosomes can be classified as classical, binary and trans-ethosomes and are prepared by methods such as thin film hydration, cold, hot, reverse phase evaporation and transmembrane pH gradient techniques. Mechanistically, ethanol acts as a penetration enhancer that fluidizes the lipid barrier of the stratum corneum; when combined with flexible vesicles, ethanol creates a synergistic interaction with skin lipids to drive deep tissue penetration. This appraisal summarise that, ethosomes are better transdermal carriers than conventional liposomes and greatly enhance the bioavailability, analgesic and anti-inflammatory effects of phyto-constituents like wintergreen oil, mentha oil, capsaicin, turmeric, lavender and Nirgundi.