Intestinal Absorption Characteristics of Promethazine Hydrochloride in Rat Single-pass Intestinal Perfusion Model / 医药导报

ABSTRACT

Objective To study the absorption characteristics of promethazine hydrochloride in different parts of rat intestine, provide evidence for the development of new preparation. Methods Rat single-pass intestinal perfusion model was established. By using high performance liquid chromatography (HPLC), 25, 50, 100 μgmL-1 promethazine hydrochloride concentration changing in different parts of the intestine was detected. Through the relevant calculation, the absorption rate constant ( Ka ) , and the apparent absorption coefficient ( Papp ) were obtained. Results With the concentration increase of promethazine hydrochloride in duodenal and ileal segments, the Ka and Papp increased significantly in the same part. Ka was (28.00±0.02)×10-2min-1 and Papp was (9.64±0.22) in the jejunum were the highest when the promethazine hydrochloride concentration was 50 μgmL-1 . As the concentration increased in colon, there were no significant changes in Ka and Papp . Conclusion Promethazine hydrochloride is absorbed in various intestinal segments, most obviously in duodenum and ileum, the absorption order is duodenum>ileum>jejunum>colon. Promethazine hydrochloride is absorbed most in the small intestine, in line with the intestinal absorption characteristics.