Preparation, Optimization, In vitro Evaluation and Ex vivo Permeation Studies of Finasteride loaded gel Formulations Prepared by using Response Surface Methodology

Objectives: The aim of the present explorative study was to prepare and optimize finasteride loaded topical gel formulations by using three factor [propylene glycol (PG), Tween (R) 80, and sodium lauryl sulphate (SLS)], five level central composite design. Results: Optimized finasteride topical gel formulation (F4), containing PG, Tween (R) 80, and SLS in a concentration of 0.8 mg, 0.4 mg and 0.2 mg, respectively, showed 6-fold higher values of cumulative drug release, flux, partition coefficient, input rate, lag time, and diffusion coefficient, when compared to control formulation without permeation enhancer. Conclusion: Finally, it can be concluded that finasteride permeation was enhanced by PG, tween (R) 80 and SLS individually, while in combination only PG along with tween (R) 80 had synergistic and more pronounced effect on flux, permeability coefficient and input rate while antagonistic effect on lag time and diffusion coefficient was observed.