Development and Characterization of Tacrolimus Liposomal Gel for Industrial Application

Objective: The objective of the present study was to prepare tacrolimus liposomal gel formulations using ethanolic injection technique for efficacious and cost-effective treatment of atopic dermatitis. Methods: The liposomes were prepared using ethanolic injection technique at the drug concentration of 0.1% w/v and optimized by varying the lipid component/ cholesterol ratio and by monitoring particle size, polydispersity and entrapment efficiency. The optimized composition was incorporated into 0.5% Carbopol Ultrez 10 gel for topical application. The developed liposomal gel was evaluated with respect to physicochemical parameters such as pH, viscosity, rheometery and spreadability. Stability study was performed at different temperatures (4°C, 25°C and 40°C) to evaluate the long-term stability. In vitro permeation of tacrolimus gel was studied using freshly excised rat skin on Franz diffusion cell. The therapeutic efficacy study was performed on allergic contact dermatitis model in rats. Results: Stable tacrolimus liposomal gel was successfully formulated using ethanolic injection technique. In-vitro permeation study indicated higher release of the drug (69.7%) as compared to free drug in hydroalcoholic solution (32.8%) and marketed ointment (63.7%). The formulation also showed shear thinning performance, which is a required property of topical formulation. The therapeutic efficacy study in rats indicated that liposomal gel containing 0.1% tacrolimus exhibited better activity as compared to 0.1% marketed tacrolimus ointment. Conclusion: The study indicated that tacrolimus can be effectively incorporated in liposomes by commercially viable rapid ethanolic injection method and can be more efficient for the treatment of atopic dermatitis.