Study of Nasal Absorption Characteristics of Gastrodin

OBJECTIVE To investigate in vitro and in vivo nasal absorption characteristics of gastrodin, so as to provide the basis for the study of gastrodin nasal preparation. METHODS In vitro nasal absorption characteristics of gastrodin was evaluated by using Franz diffusion cell with fresh pig nasal mucosa as permeation barrier and mucosal permeation coefficient as index. In rat nasal circulatory perfusion experiment, using medicated normal saline for nasal liquid circulation, the content of gastrodin was determined by HPLC to investigate the in vivo nasal absorption characteristics. RESULTS Mucosal permeation coefficient in vitro of fresh pig nasal were respectively 1.9×10^-3, 1.3×10^-3, 4.3×10^-3 cm^-2·min^-1 in gastrodin group with low dose, middle dose and high dose; Absorption rate constants in rat nasal circulatory perfusion experiment were respectively 2.9×10^-3, 6.0×10^-3, 2.4×10^-3 min^-1. Mucosal absorption amount of gastrodin were increased with increasing drug concentration, but the absorption rate constant was small, and mucosal absorption amount of gastrodin group with middle concentration was better than low concentration and high concentration. CONCLUSION Although gastrodin can be absorbed through nasal mucosa, its absorption rate constant and mucosal permeation coefficient are small, which means that it is needed to increase the absorption of nasal mucosa by increasing the osmotic agent or changing the dosage form in the preparation of gastrodin nasal administration.