Physical Approaches to Penetration Enhancement
Transdermal delivery of drugs through the skin to the systemic circulation provides a convenient route of administration for a variety of clinical indications. For transdermal delivery of drugs, stratum corneum is the main barrier layer for permeation of drug. So to circumvent the stratum corneum and to increase the flux through skin membrane, different approaches of penetration enhancement are used. Many reviews had described regarding iontophoresis, electroporation, sonophoresis, phonophoresis but other physical method of penetration enhancement like magnetophoresis, laser radiation and photomechanical waves, radio frequency, thermophoresis, microneedle based devices, skin puncture and perforation, needleless injection, suction ablation, application of pressure, skin stretching, skin abration are not exploited for reviews. These physical methods are used extensively to enhance permeation of drugs through skin. The review presents mainly the routes of penetration through skin and the physical approach of penetration enhancement to optimise the transdermal delivery system.
Keywords: Transdermal; Penetration enhancement; Physical method; Skin.