Preparation of dry powder inhalation of yuanhuacine and its tissue distribution in rats

The aim of the present study was to increase distribution of yuanhuacine in the lungs and achieve the purpose of reducing toxicity and increasing efficiency. Therefore, yuanhuacine was designed to be dry powder inhalers innovatively and directly delivered to the lungs. Accordingly, inhaled lactose was used as a carrier to adsorb yuanhuacine on the surface of lactose. Fine particle fraction(FPF)was utilized as evaluation index to filtrate the optimal prescription for pulmonary administration. Besides, an UHPLC-MS/MS method was established for the analysis of heart, liver, spleen, lung, kidney, brain and reproductive system of rats. Intravenous injection was taken as reference to investigate the distribution of yuanhuacine and calculate relevant targeting parameters. The experimental result indicated that the prescription(rough lactose ∶fine lactose=10 ∶1)has the highest FPF, which can be chosen as the most suitable prescription for pulmonary administration of yuanhuacine. Moreover, by comparing the distribution of yuanhuacine through pulmonary administration and intravenous injection, it was found that the concentration of yuanhuacine in the lung tissue was greatly increased by pulmonary administration, which decreased the distribution in heart, liver, spleen, kidney, brain and reproductive system, thus sequentially reducing the toxicity in other tissues and increased the efficiency.