Permeation Studies and Histological Examination of Sheep Nasal Mucosa Following Administration of Different Nasal Formulations with or without Absorption Enhancers

This study was designed to investigate the possible histological effects of different intranasal (IN) formulations of indomethacin (IND) on nasal mucosa in sheep. For this purpose, oil-in-water (O/W) emulsion (E) and solution (S) formulations including 3 mg/mL of IND were prepared. Penetration enhancers such as polyvinylpyrolidone (PVP), citric acid (CA) and sodium taurocholate (NaT) were added to emulsion (1%) at the final step into the formulations. First, the effect of penetration enhancers on permeation of IND was evaluated by in vitro permeation studies in which sheep nasal mucosa was used. According to the permeation studies PVP showed the highest enhancing effect on the permeation rate of IND from sheep nasal mucosa. Furthermore, the IND permeation from E containing PVP (1.624 ± 0.045 mg) was significantly higher than that obtained from E (0.234 ± 0.012 mg) (p < 0.05).