RESUMO
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 enteric-coated 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
RESUMO
Objective: To establish the quality standard for Dibu Gengnian 'an granules. Methods: Fructus Schisandrae, Radix Pueaariae, Radix Angelicae Sinensis, Fructus Psoraleae and Radix Glycytthizae in the formula were identified by TLC. The content of puerarin in the formula was determined by HPLC. The determination was performed on a Welchrom C18 (200 mm × 4. 6 mm, 5 μm) column with the mobile phase consisting of methanol-0. 5% glacial acetic acid (25∶75) at the flow rate of 1. 0 ml·min-1 . The detec-tion wavelength was set at 250 nm, and the column temperature was 25℃. Results:The spots in TLC were clear with good separation and specificity. The linearity of the calibration curve was good within the range of 5-120 μg·ml-1 for puerarin (r=0. 999 8). The RSDs of precision, stability and reproducibility tests were all lower than 3%. The average recovery was 99. 09% (RSD=2. 38%, n=6). Conclusion:The method is simple, specific, accurate and reliable. It can be used in the quality control of Dibu Gengnian’an granules.