Formulation and evaluation of clotrimazole transdermal spray

<p><i>Context</i>: Transdermal spray (TS) of clotrimazole (CTZ) was formulated to improve the drug transport through the skin up to 12 h to achieve the antifungal efficacy.</p> <p><i>Objective</i>: The aim of present study was to formulate and evaluate antifungal transdermal spray to improve the permeation of clotrimazole across the skin and to decrease the dosing frequency in fungal infection.</p> <p><i>Materials and methods</i>: Different ratios of ethanol and acetone and various grades of eudragit and ethyl cellulose were evaluated according to six criteria: viscosity, drying time, stickiness, appearance and integrity on skin and water washability. Propylene glycol (PG) and polyethylene glycol 400 (PEG 400) were used in the study as plasticizer and solubilizer. The TS was evaluated for <i>in vitro</i> drug release, spray angle, spray pattern, average weight per dose, pH, drug content, evaporation time, leak test and antifungal efficacy study.</p> <p><i>Results and discussion</i>: Eudragit E100 and blend of ethanol and acetone (80:20) satisfied the desired criteria. The selection of optimized batch was based on the results of <i>in vitro</i> drug release, spray pattern and spray angle. The optimized batch showed the spray angle <85° and uniform spray pattern. The formulation containing PG showed higher drug release than PEG 400. The inclusion of eutectic mixture consisting of camphor and menthol (1:1) showed improved drug transport through the rat skin and larger mean zone of inhibition indicating the improved antifungal efficacy.</p> <p><i>Conclusion</i>: The TS of CTZ can be an innovative and promising approach for the topical administration in the fungal diseases.