Transfersomes: The Ultra-Deformable Carrier System for Non-Invasive Delivery of Drug

Vesicular systems have many advantages like prolonging the existence of the drug in the systemic circulation, minimizing the undesirable side-effects and helping the active moieties to reach their target sites using the carriers. However, the main drawback related to transdermal delivery is to cross stratum corneum, which can be overcome by the utilization of novel carrier systems e.g., transfersomes, which are ultra-deformable carrier systems composed of phospholipid (phosphatidylcholine) and edge activators (surfactants). Edge activators are responsible for the flexibility of the bilayer membranes of transfersomes. Different edge activators used in transfersomes include tween, span, bile salts (sodium cholate and sodium deoxycholate) and dipotassium glycyrrhizinate. These activators decrease the interfacial tension, thereby, increasing the deformability of the carrier system. Transfersomes can encapsulate both hydrophilic and hydrophobic drugs into a vesicular structure, which consists of one or more concentric bilayers. Due to the elastic nature of transfersomes, they can easily cross the natural physiological barriers i.e., skin and deliver the drug to its active site. The main benefit of using transfersomes as a carrier is the delivery of macromolecules through the skin by non-invasive route thereby increasing the patient's compliance. The transfersomal formulations can be used in the treatment of ocular diseases, alopecia, vulvovaginal candidiasis, osteoporosis, atopic dermatitis, tumor, leishmaniasis. It is also used in the delivery of growth hormones, anaesthesia, insulin, proteins, and herbal drugs. This review also focuses on the patents and clinical studies for various transfersomal products.