Formulation development of topical solutions of poorly water-soluble drug indomethacin employing novel application of mixed solvency concept and their evaluation

Abstract

Aim: Application of mixed solvency concept has been employed in the present research work to develop the topical solution formulations of poorly water-soluble drug indomethacin (as a model drug). Material and Method: Due to the low solubility of indomethacin in water, combination of solubilizers as mixed solvent systems was used to decrease the overall concentration of solubilizers required to produce a substantial increase in solubility and thereby resulting in enhanced permeation of indomethacin from its topical formulation. The procured sample of indomethacin was characterized by melting point, infrared, ultraviolet, and differential scanning calorimeter studies. The formulations were evaluated for various properties of a solution such as pH, viscosity, freeze-thaw study, and thin layer chromatography. Stability studies of topical indomethacin solutions were performed for 2 months at room temperature, 30°C and 40°C. Result: The results of stability studies of indomethacin topical solution were satisfactory. It was found that 95.07%, 93.88% and 93.45% of drug was remaining after stability study at respective temperatures in batch first and 94.89%, 94.44% and 94.32% in batch second. Conclusion: Mixed solvency concept successfully employed to improve the drug loading of poorly water soluble drug indomethacin.