We tried to evaluate the role of different organs in the low bioavailability by administering the drug by different routes. It indicates that either the drug is poorly absorbed or undergoing metabolism in the git. It is stable in gi contents. We analysed portal and venous samples after a single oral dose in rats to get an idea of the amount of drug being actually absorbed. Although a metabolite was observed in portal vein samples also its concentration is not that significant to really account for such a loss.
Suggestions are welcome.