Development And Evaluation Of Peppermint Oil Containing Microemulsions For Intranasal Delivery

Objective: To develop and formulate a non toxic, user-friendly, and comfortable intranasal spray formulation of peppermint oil for alleviating migraine. Materials and Methods: Peppermint oil, Tween80, Span80, PEG400, nasal spray pumps, reagents and solvents of analytical grade were used. Microemulsions were prepared by water titration method. Effect of 1% glycerin on formulation viscosity was studied. VP7/100A, VP7D/100A and VP6/100A spray pumps were evaluated for spray pattern, shot weight and spray content. Invitro and Exvivo diffusion studies were carried through cellulose acetate membrane and sheep nasal mucosa respectively. In vivo efficacy was assessed with Digital Actophotometer. Results: Formulations were developed using (Smix) Tween 80: Span 80 in the ratios of 1:0.25 and 1:0.5, PEG 400 (0.5 gm) and glycerin (1%). These were stable, clear with pH of 4.5 to 6.5 and viscosity was 304.5cps. Vp6/100A exhibited the most consistent spray and uniform delivery amongst the tested pumps. The amount of drug diffused was 80% through cellulose acetate membrane and 75%through sheep nasal mucosa within 24hrs. Histopathological studies revealed no significant irritation and damage to nasal mucosa. 74% inhibition of motility was seen with the developed formulations. Conclusion: Developed intranasal spray formulations containing peppermint oil showed potential to alleviate migraine.