Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9901494 | European Journal of Pharmaceutics and Biopharmaceutics | 2005 | 5 Pages |
Abstract
The bioavailability of orally administered drugs can be influenced by interactions with food components and by physico-chemical conditions in the upper gastrointestinal tract. Normally, bile salts enhance the transport of lipophilic drugs across mucosal membranes. Bile salts are able to form stable mixed micelles consisting of fatty acids and phospholipids. Conventional micellar systems are known to solubilize lipophilic drugs having a low bioavailability. The influence of bile salts and mixed micelles on the pharmacokinetics of the lipophilic drug quinine was investigated in rabbits. Female rabbits were given intraduadenally quinine (5Â mg/kg body weight) without and with incorporation into the micellar or mixed micellar systems. Blood was collected every 30Â min for 6Â h. In plasma, concentration of quinine was measured using HPLC. The plasma concentration-time profiles of quinine were significantly lower within the first 2Â h after administration in presence of both the sodium salt of glycodeoxycholic acid (above the critical micellar concentration) as well as of mixed micellar systems consisting of glycodeoxycholic acid and palmitic acid and/or lecithin. The pharmacokinetic parameters AUC (relative bioavailability) and cmax of quinine were significantly decreased by micellar systems in rabbits. These mixed micellar systems lower and not as expected, increase the absorption of quinine in vivo. Therefore, quinine should be orally administered at least 1Â h before food intake, particularly before fat intake.
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Authors
Gerhard Dongowski, Bertram Fritzsch, Jochen Giessler, Albert Härtl, Olaf Kuhlmann, Reinhard H.H. Neubert,