Topical Film Forming Clotrimazole Emulgel

Introduction: Clotrimazole is a weak base and is practically insoluble in water. To enhance drug loading of hydrophobic Clotrimazole in the formulation and, to circumvent greasiness, poor retention time and easy wipe off associated with conventional topicals, it was formulated as a Film Forming Emulgel. Materials and Methods: Preformulation studies were performed to evaluate solubility and emulsification of drug in oils and surfactants, and screening of gelling and film forming agents. Capryol 90 and Tween 80 were selected as the oil and surfactant, respectively. Sepineo P 600 and HPMC E4M were selected as the gelling agent and film forming agent respectively. The films were evaluated for peelability, tackiness, folding endurance, swelling index and cosmetic attractiveness. Results: The optimized formulation formed clear, uniform and adhesive films and exhibited similar in vitro and ex vivo release profiles, to that of the marketed product (α = 0.05, p=0.605 for in vitro diffusion). Dry and wet swab studies performed on the optimized formulation presented that the film formed exhibits good adhesion, lowered drug loss associated with wipe off and enhanced retention. In vivo dermal irritation test on Sprague-Dawley rats was also carried out. Release profiles were compared using multiple models with first order release being the best suited model for the optimized formulation (R2= 0.9932) and marketed product (R2=0.9859). Stability studies performed helped conclude the optimized formulation was stable. Conclusion: The developed formulation is an excellent alternative to emulgel and patches, overcoming the drawbacks of each by giving longer retention on the skin for prolonged therapy.