Preparation and evaluation of minoxidil foamable emu oil emulsion

The aim of this work was to develop and evaluate a minoxidil foamable emu oil emulsion with the purpose of improving minoxidil permeation into the skin, increasing hair growth, reducing skin irritation, and increasing consumer compliance. Minoxidil was dissolved in a solvent system comprising ethanol: glycerin: lactic acid: water (10:20:5:65). The foamable emulsion was prepared by mixing the oil phase with minoxidil solution using different amount of various emulsifiers. Seventeen formulations were prepared and the most stable foamable emulsion was selected and evaluated for various pharmaceutical parameters such as homogeneity, pH, stability to centrifugal stress, freeze-thaw and foamability. The adopted formulation showed good pharmaceutical characteristics. In vitro release rate of the formulations were evaluated using Franz diffusion cell using phosphate buffer pH 7.4 and ethanol as the receiver medium at sink condition. The release rate of formulations was found to obey Higuchi kinetic model. Experimental animal study was performed to evaluate hair growth potential of the formulation. Different cyclic phases of hair follicles, like anagen, and telogen phases, were determined at one month period. Histological study after treatment with adopted formulation exhibited greater number of hair follicles in anagenic phase (96%) which were higher as compared to marketed 5% minoxidil solution (Pakdaru® 70%) and the control group (42%). From animal study it was concluded that the selected formulation exhibited a significant potency in promoting hair growth in comparison with marketed 5% minoxidil solution Pakdaru®.