美沙拉嗪肠溶缓释颗粒剂的大鼠药动学及胃肠道分布研究.

Objective　To evaluate the pharmacokinetics of the new mesalazine enteric-coated sustained-release granules in SD rats and their distribution in the gastrointestinal tract, and to understand the preclinical pharmacokinetics and gastrointestinal distribution characteristics of the preparation. Methods　Rats were administered orally to determine the drug concentrations in plasma samples and in the gastrointestinal tract. The commercially available mesalazine sustained-release granule was used as a reference to self-developed one to evaluate the process of absorption and elimination in vivo, relative bioavailability, and distribution in the gastrointestinal tract. Results　The relative bioavailability of mesalazine enteric-coated sustained-release granule and non-enteric-coated one characterized by mesalazine was 89.62% ± 9.36%. After oral administration of mesalazine entericcoated sustained-release granules, the drug has a high concentration distribution in the stomach within 2-8 hours, and gradually enters and remains in the jejunum, ileum and colon over time for 6-12 hours and then reaching a high concentration distribution in the colon. This help for the absorption of mesalazine, as well as the fixed-point release of the drug to produce a therapeutic effect. Conclusion　The absorption and elimination process of mesalazine enteric sustained-release granule showed linear kinetic characteristics. There was no significant difference in pharmacokinetic parameters from the commercially available formulations, and it had a certain fluidity in the gastrointestinal tract. Good gastrointestinal distribution characteristics help the absorption of drugs in the body and the targeted release of the site of action. [ABSTRACT FROM AUTHOR]