Occupancy, Half Value Duration, Plateau Time in Phoenix/WinNonlin 8 [R for BE/BA]

posted by Astea – Russia, 2017-10-31 01:12 (1543 d 20:17 ago) – Posting: # 17957
Views: 20,342

Dear Helmut!

Thank you for the detailed explanation!

Now everything became clear excepting directly intersections. If the calculation of TimeLow and TimeDur are based on the difference between intersections, why are they not included into output or elsewhere? Of course, the structure of the curve should be more complicated and there could be several intersections...

So, how to get pointed values 0.595 to 8.386 or 0.595 to 8.257 not by hand, brain, R, Excel but by Phoenix?

For a single peak chart I come up with insane ideas of initial data manipulation namely truncating or reflecting the curve.

For example, with the mentioned dataset:
  1. cutting data from 0 to Cmax we'll get TimeLow=T50%early =0.595056.
  2. cutting data from Cmax to Tlast and moving graph to zero we'll get T50%late equal to TimeHigh+Tmax= 8.386133 or 8.256799 depending on the selected trapezoidal method.
  3. reflecting the decreasing part of the curve (that is for Ct>Cmax Ct->2Cmax-Ct) and choosing Lower=0.5Cmax, Upper=1.5 Cmax, we'll get together linear TimeLow=T50%early=0.595056 and TimeLow+TimeDur=T50%late=8.386133.


Looks mad, can it be made easier?

"Being in minority, even a minority of one, did not make you mad"

Complete thread:

 Admin contact
21,835 posts in 4,569 threads, 1,554 registered users;
online 5 (1 registered, 4 guests [including 3 identified bots]).
Forum time: Friday 21:29 CET (Europe/Vienna)

No problem can stand the assault of sustained thinking.    Voltaire

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