What's the difference between food and drug kinetics in human body?

I'm working with PK data of drug X that is majorly excreted unchanged into the urine (60-70%), but also has one metabolite excreted into the urine (30-40%). AUC and Ae of drug X and Ae(m) were measured. Metabolite concentrations in plasma were very low and undetectable. Thus, I was using the following equation to estimate formation clearance of the metabolite:

Cf = Ae(m) / AUC (of drug X).

However, this equation assume that all drug X is metabolized F(m) = 1. That's not the case. Thus, how to estimate formation clearance when F(m) is not unity?

Additionally, metabolism seems to be occurring in a higher extend in the kidneys, not the liver.

Thank you!

We all know that digestive enzymes speed up the chemical reaction and helps in food digestion. I was wondering if in general it takes 6 h to digest a food with the help of digestive enzymes then how long will it take our body to digest food in case no digestive enzyme are present?

GLP-1 is an incretin hormone produced by intestinal L cells and the brain. GLP-1 is released in response to food intake to stimulate glucose-dependent insulin secretion by the pancreas. Additionally, GLP-1 exerts multiple other effects, including inhibition of food intake, slowing gastric emptying, and inhibition of glucagon secretion. Thus, GLP-1 was considered as a good target for the treatment of T2DM. However, therapeutic application of GLP-1 is hampered due to its short circulating half-life (<2 minutes), because it is rapidly degraded by dipeptidyl peptidase 4 (DPP-4) that is widely expressed in endothelium and intestinal mucosa.

Can we improve pharmacokinetics for GLP-1 analogues to increased the half-life for the better treatment of Type 2 Diabetes Mellitus. And How we improve pharmacokinetics?

What should be the dose I should use of the digested foods?

How long should I wait before measuring TEER?

How many days should I put food in the cells and make the measurement?

Your stomach is a chemical reactor. When you devour a fast food Samosa in

about a minute, it acts like an instantaneous input of 325 g of food entering

the stomach. In response, the stomach starts producing gastric liquids (acids),

which are continuously excreted into the stomach at a rate of 12.0 mL/min as

Samosa is digested. The fluid also leaves the stomach to the small intestine at

a flow rate of 12.0 mL/min, so the volume of liquid in the stomach stays

constant at 1.15 L. The Samosa digestion rate constant is 1.33 hr-1.

What fraction of Samosa mass will remain undigested in your stomach one

hour after you eat the Samosa?

Effect of proventricular enzymes on lipids and carbohydrates.

For example, When drug act directly on alveoli then how drug is metabolized?