Formulation and development of vaginal films of poorly water soluble drug, metronidazole, using mixed solvency concept and their evaluations

Aim: To deliver antibacterial therapy in an efficacious way, film dosage form has been proposed for drug delivery in vagina which can overcome bioavailability issues of poorly water soluble drugs. The present research work is aimed to explore the application of mixed solvency concept to increase solubility of poorly water soluble drug, metronidazole. Materials and Methods: Metronidazole, a slightly soluble drug in water was tried to be solubilized by employing the combination of solubilizers like niacinamide, sodium benzoate, sodium caprylate, caffeine and urea to endeavour its fast dissolving film formulations. The procured sample of drug was characterized by UV, IR and DSC studies. The formulations were evaluated for various properties of film such as thickness, folding endurance, surface pH, disintegration time and thin layer chromatography. Stability studies of vaginal films of metronidazole were performed for ten weeks at room temperature, and refrigerated conditions. Results and Discussion: It was found that 97.54% and 97.58% of drug was remaining after stability study at respective temperatures in batch F1 and 98.53% and 96.57% in batch F4.Conclusion: It was concluded that the approach of mixed solvency concept is novel, safe, cost-effective and user friendly. It also eliminates the problem of toxicity associated with high concentration of water-soluble solubilizers. So, it may be employed in dosage form development of drugs with poor solubility to overcome bioavailability issues. Keywords: Solubility, metronidazole, vaginal films, mixed solvency concept.