Biopharmaceutics

The processes of drug disposition in the body (absorption, distribution, metabolism and excretion) are recognized to be important as factors that determine drug concentration at the site of action and, thereby, affect therapeutic effects. We are pursuing drug disposition studies to understand underlying mechanisms and to help finding and/or developing dosage forms and dosage regimens that can achieve optimal or, even, controlled disposition of drugs, and, further, drug molecules with desired disposition characteristics. Studies of particular emphasis include those on intestinal drug absorption and on membrane transporters, which have been increasingly recognized for their roles in drug disposition. Searches for novel (unidentified) transporters are also attempted.

(1)Role of multidrug and toxin extrusion protein 2 (MATE2) as an organic cation/H+ antiporter in the renal excretion of cationic drugs.

(2)Increased absorption of nifedipine by Lactobacillus casei (L. casei), a strain of probiotic bacteria, in rats: model analysis of plasma concentration data.