Nasal drug delivery of sumatriptan succinate.

The purpose of this work was to increase the nasal absorption of sumatriptan succinate by using bile salts. A rat in situ nasal perfusion technique was used to examine the rate and extent of absorption of sumatriptan succinate. In vitro enzymatic drug degradation studies were carried out with rat nasal washings. Various experimental conditions such as nasal perfusion rate, pH of the perfusion medium and concentrations of absorption enhancers such as sodium deoxycholate, sodium caprate, sodium tauroglycocholate and EDTA were optimized. In vivo studies were carried out for the optimized formulation in rabbits and the pharmacokinetics parameters of nasal solution were compared with marketed nasal solutions. Nasal absorption of sumatriptan succinate was pH dependent. It was found maximum at pH 5.5 and decreased at higher pH values. In in vitro enzymatic degradation studies, no measurable degradation was observed during the first week. The extent of drug absorption was increased by absorption enhancers. Sodium deoxycholate appeared to be more effective for enhancing the nasal absorption of sumatriptan succinate than the other absorption enhancers. The order of increasing absorption of sumatriptan succinate caused by theenhancers was sodium deoxycholate > sodium caprate > sodium tauroglycocholate > EDTA.