how does cmax decrease over time in human body? Does that work with halflife calculation?

[Cheeeeesseeeey]

I'm interested in chemistry but it's all new for me and I'm just starting out. I tried to do some calculations but got stuck...

I was wondering, for example a supplement has the following values:

Molar mass: 306.247 g mol-1

Tmax 2-4 hours

Cmax 363.3 ng / ml

Half life: 11.21 hours

How do you calculate the ng / ml after 5 days at dosing 100mg? Since that 363 ng/ml is at the peak between 2-4 hours if I'm not mistaken?

If you use the half life calculation you get a value of ~0.097mg in the system but I assume that it differs per ml for how much someone weighs? Someone at 80kg is probably different then 100kg?

[chenbeier]

What does dosing 100mg and Tmax 2-4 h mean.

You have a start concentration of 363,3 ng/ml, you have given half life time 11.21 h and a time 5 days

Decay rate is 0.5*A(0) = A(0)* e^(-k*11.21 h)

 -0,693 = - k* 11.21 h => k= 0,06183*h^-1

5 days = 120 h

A(5d) = 363,3ng/ml* e^(-0,06183*h^-1*120h)

A(5d) = 0,217 ng/ ml is left after 5 days.

 

Where do you put the 100 mg and the Tmax.

Edited July 31, 2022 by chenbeier