Transport of limonin in rat intestine in situ and Caco-2 cells in vitro / 药学学报

Limonin existed in citrus fruits has been shown to have anti-bacterial, anti-viral, anti-feedant, anti-nociceptive, anti-inflammatory activities and anti-carcinogenic activities. But the clinical use is limited by its low bioavailability. The aim of this study is to observe the absorption and secretion transport mechanisms of limonin in intestine which can pave the way for the further study and clinical use. The transport characteristics and mechanisms of limonin in rat were studied by in situ intestine perfusion and in vitro Caco-2 cells method. The intestinal absorption of limonin was probably via a facilitated diffusion pathway which was poor and without segment-selection. Verapamil and ketoconazole improved the absorption remarkably according to the result of in vitro Caco-2 cells study; however, probenecid had no significant effect on the absorption. The P-gp efflux and CYP3A4 metabolism were involved in the poor intestinal absorption and low bioavailability of limonin. The exploration of the intestinal absorption mechanism is crucial to the design of dosage form and clinical use of limonin.

Micromeritic evaluation of the direct compression excipient LubriTose AN / 药学学报

This study is to report the evaluation of the micromeritic properties of LubriTose AN, which is expected to provide preliminary theoretical basis for the direct compression technology. From the aspects of flowability, compressibility and dilution potential, the angle of repose, flow velocity, the Carr' index, tensile strength, elastic recovery, yield pressure and the lubricating ability of LubriTose AN were determined. Also, model drugs were selected to investigate the dilute potential under the desirable compressing performance. Compared to the physical mixtures, the flowability of LubriTose AN was better, and the deformation mechanism was the same with anhydrous lactose, both brittle deformation. The compressibility and compaction of LubriTose AN was slightly better than that of physical mixtures under low and moderate pressure. The dilution potential of LubriTose AN were high for most of hydrophobic drugs. The lubricate ability was desirable under different rotational speeds. LubriTose AN is an excellent co-processed excipient, which is helpful for the promotion and improvement of the tablet manufacturing level.