Pharmacokinetic Interaction of Some Antitubercular Drugs with Caraway: Implications in the Enhancement of Drug Bioavailability

This study deals with the pharmacokinetic interaction of selected anti-TB drugs with a natural product (CC-1a) derived from caraway (Carum carvi, L.) seed. CC-1a, chemically standardized butanolic fraction, enhanced the plasma levels of rifampicin, pyrazinamide, and isoniazid in Wistar rat, resulting in increased bioavailability indices (C(max) and AUC) of the drugs. Moreover, a 40% reduced dose regimen of these drugs, which additionally contained CC-1a, was equivalent in terms of C(max) and AUC to a normal dose regimen. A permeation-enhancing property of CC-1a across small intestinal absorptive surface was found to be a contributing factor in its bioavailability enhancing profile.