Steady state calculation using WinNonlin [Software]

posted by Helmut Homepage – Vienna, Austria, 2007-06-27 13:56 (6119 d 03:42 ago) – Posting: # 840
Views: 18,596

Dear Imran!

❝ 1. should trough concentrations and concentration of profiling day should

❝ be run separately or in the same set of data to generate PK parameters?

Also beware of (quoting the manual):

Time deviations in steady-state data
When using steady-state data, WinNonlin computes AUC from dose time to dose time + tau, based on the tau value set above. However, in most studies, there will be sampling time deviations. That is, if dose time = 0 and tau = 24, the last sample might be at 23.975 or 24.083 hours. In this instance, the pro­gram will estimate the AUC based on the estimated concentration at 24 hours, and not the concentration at the actual observation time. For steady state data, Cmax, Tmax, Cmin and Tmin are found using observations taken at or after the dose time, but no later than dose time+tau.


❝ 2. Should only trough values should be used for calculation of % fluctuation?


:confused: %fluctutation (or %Peak-to-Trough Fluctuation, %PTF) is defined as:
\(\small{\%PTF=100\frac{C_{\textrm{max}}-C_{\textrm{min}}}{C_{\textrm{av}}}}\)
where \(\small{C_{\textrm{av}}=AUC_{\tau}/\tau}\), and \(\small{C_{\textrm{max}}}\), \(\small{C_{\textrm{min}}}\) refer to extremes of the profile in steady state.

In WinNonlin you have to calculate %PTF manually (it's not given in the result workbook).

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz
[image]

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes

Complete thread:

UA Flag
Activity
 Admin contact
22,957 posts in 4,819 threads, 1,638 registered users;
79 visitors (1 registered, 78 guests [including 6 identified bots]).
Forum time: 16:39 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