Hi, I am trying to fit a parent drug dosed orally with an active metabolite. I need to estimate the amount of the drug converted to the metabolite in the gut in addition to the amount formed by metabolite formation in plasma. I searched forums and I found a similar question from one member, but the question has not been answered.
https://support.certara.com/forums/topic/928-lesson-2-parent-and-metabolite-kinetics/?p=4236
​Can I get help especially with the first question.