Studies on absorption mechanism of loganin in intestines of rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the absorption mechanism of loganin at different intestine segments of rats and the influence of the drug solution concentration, pH, P-gp inductor.</p><p><b>METHOD</b>Rats were randomly divided into 10 groups, high, middle and low concentration groups (0.1, 0.025, 0.012 5 mg x mL(-1)), duodenum, jejunum and ileum groups (0.013 mg x mL(-1)), high, middle and low pH groups (0.013 mg x mL(-1)), inducer group (0.013 mg x mL(-1)). The intestine cannulation was performed for in situ recirculation. Loganin concentration in the flux was measured by the reversed phase HPLC.</p><p><b>RESULT</b>When the concentration was raised from 0.012 5 to 0.1 mg x mL(-1), the uptake of loganin was linearly increased, and no change of Ka is not found. The pH of flux has no effect on drug absorption. The absorbed dose and Ka sequence (from high to low) of loganin at different intestine segments is ileum, duodenum, jejunum. Furthermore, P-gp inductor RFP has effect on the intestinal absorption.</p><p><b>CONCLUSION</b>The absorption of loganin in intestine of rat is a first-order kinetics, the absorption mechanism is probably the passive diffusion. It has specific absorption locus and access to locating administration, meanwhile it's the P-gp substrate, and could increase its fraction of bioavailability by corporation with P-gp inhibitor.</p>

Comparision study pharmacokinetics of different source cinnamon acid / 中国中药杂志

<p><b>OBJECTIVE</b>To study relatively pharmacological activities of cinnamon acid in blood serum of rabbit administered cinnamon acid, cinnamon and Jingui Shenqi pills.</p><p><b>METHOD</b>RP-HPLC determine and analysis blood serum sample from rabbits administered cinnamon acid, cinnamon and Jingui Shenqi pills. Condition of colour spectrum was Symmetry C18 (3.9 mm x 150 mm, 5 microm) chromato bar, mobile phase was methanol-1% glacial acetic acid water-solution (45:55), flow rate was 0.8 mL x min(-1), temperature of bar was 35 degrees C, detection wave length was 285 nm. The serum pharmacokinetic parameters were calculated with 3p87.</p><p><b>RESULT</b>Linear range of cinnamon acid is from 0.06-15 microg x mL(-1) (r = 0.9997), the lowest detectability is 0.054 microg x mL(-1). Pharmacokinetic process of cinnamon acid in rabbit could be all fitted to two-compartment model.</p><p><b>CONCLUSION</b>Sensitive and exclusive HPLC that adopt can exactly detect serum concentration in rabbits administerd cinnamon acid. Pharmacokinetic parameters of three conditions can reveal pharmacokinetics regularity of cinnamon acid in rabbit.</p>