Factorial Design Executed Development of Miconazole Nitrate Microemulsion Based Bioadhesive Gel and Its Evaluation

Abstract

Miconazole nitrate (MN) is a poorly aqueous soluble antifungal drug. The microemulsion (ME) based bioadhesive antifungal gel of MN was designed to improve the antifungal activity by increasing the bioadhesion potential. Based on the solubility results, components of ME were selected viz. rice bran oil: tween 80: propylene glycol and proceeded with pseudo-ternary phase diagram studies. 23 factorial design was employed for the formulation of MEs employing water titration technique. The MEs was examined for further studies and was optimized using DESIGN EXPERT 12 software considering the responses like globule size, zeta potential and in vitro drug release. Tamarind seed polysaccharide (TSP) and carbopol 934 were used as gel bases for the formulation of microemulsion-based bioadhesive gels. The gels were examined for drug content, pH, spreadability, viscosity, bioadhesive strength, ex vivo drug permeation and in vivo skin irritation potential. The antifungal activity against Candida albicans and Cryptococcus neoformans of four formulations (MN-ME, MN- ME based TSP gel, MN- ME based carbopol gel and marketed miconazole gel (2% Miconazole gel) was evaluated using modified agar diffusion method. The results revealed that microemulsion based bioadhesive gel (MBG) of TSP and CP exhibited drug content of about 87.29% and 83.34% and ex vivo skin permeation of 84.21% and 73.94% at the end of 10 h. MBG of TSP showed better antifungal activity and no skin irritation potential in comparison to the carbopol gel. Therefore, MBG of TSP has the ability to enhance the contact time owing to greater bioadhesion thereby providing a better therapeutic activity. Keywords: Miconazole nitrate, Tamarind Gum, Topical delivery, Microemulsion based bioadhesive gel, fungal infection.