Potency correction: Rather why than when [Regulatives / Guidelines]

posted by ElMaestro  – Denmark, 2018-06-25 12:22 (2103 d 12:22 ago) – Posting: # 18958
Views: 5,305

Hi Hötzi,

❝ let’s consider the basics. We have a set of two equations

  1. AUCT = ƒT·DT/CLT

  2. AUCR = ƒR·DR/CLR
which consist of eight variables. We are interested to compare the bioavailabilities or ƒTR (not the individual values ƒT and ƒR), reducing the variables to seven.


You are on the right track. I think this was largely an answer to a question I didn't ask, and not answer to the question I asked. I believe I once again perhaps did not explain myself properly enough.

I will try and use your own language:
AUCT/AUCR=(fT/fR)(DT/DR)(CLR/CLT)
where we will assume CLT=CLR, so
AUCT/AUCR=(fT/fR)(DT/DR) or
(DR*AUCT) / (DT*AUCR) = fT/fR or

(DR/DT)*(AUCT/AUCR)=fT/fR

This multiplication by the dose ratio is essentially what the potency correction achieves. You can rearrange that also in another outright horrible fashion:

(AUCT/DT) / (AUCR/DR) = FT/FR

Ouch. Potency correction is the wonderful tool I can use to prove that 5x250 mg Schützomycin tablets are bioequivalent to 1x250 mg Schützomycin :-). Let us for the purpose of this discussion leave out non-linear kinetics etc.

Pass or fail!
ElMaestro

Complete thread:

UA Flag
Activity
 Admin contact
22,957 posts in 4,819 threads, 1,636 registered users;
80 visitors (0 registered, 80 guests [including 12 identified bots]).
Forum time: 23:45 CET (Europe/Vienna)

Nothing shows a lack of mathematical education more
than an overly precise calculation.    Carl Friedrich Gauß

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5