Topical delivery of Tacrolimus using liposome containing gel: An emerging and synergistic approach in management of psoriasis.

Psoriasis is a chronic relapsing inflammatory and hyperproliferative skin disease affecting quality of life. It affects an estimated 8 million Americans and more than 125 million people worldwide. The estimated cost to treat psoriasis in USA is over 13 billion US dollars per year. Treatment of psoriasis may include topical steroid-sparing agent, topical corticosteroids, phototherapy or biologics. Tacrolimus has 10-fold greater immunosuppressive activity than the ciclosporin A which has been recommended for effective treatment of psoriasis. However, it has been widely investigated using conventional formulation approaches which limit its clinical outcomes. It has poor cutaneous bioavailability when administered topically using conventional delivery approach, thus it has poor efficacy against the psoriasis. Low aqueous solubility and high degradation of Tacrolimus make it difficult to formulate as a liquid preparation. Moreover, Tacrolimus has narrow therapeutic index and thus it is essential to prevent its possible toxic effects when a modified release dosage form is administered. The present hypothesis aims to put forward to incorporate Tacrolimus into a novel lipid based nanocarrier system, which would be further loaded into a hydrogel base and evaluated for its target specific topic delivery. Due to the structural similarity of the lipid nanocarriers and skin, these vesicles would target the skin tissues effectively and treat psoriasis with minimum or no side effects. Thus, the proposed formulation would be a considerable value addition to the current therapeutic approaches used for psoriasis management.