Bioequivalence and Bioavailability Forum

Intersections [🇷 for BE/BA]

posted by Helmut  – Vienna, Austria, 2017-10-31 13:32 (2361 d 23:30 ago) – Posting: # 17958
Views: 22,714

Hi Astea,

❝ 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?

Ask Certara.
If there is no demand by customers it will not be implemented. Even if there is one, it may take ages. Example: The intercept of the log/linear-regression used in the estimation of λ_z was only part of the Core output (if Intermediate Output was selected) up to release 7.0… Since the EMA stated “by C_min,ss we mean the concentration at the end of the dosage interval, i.e. C_trough” in 2010 it took seven years to get both Cmin (as in previous versions) and Ctau (observed if t=τ or predicted if t≠τ) in the output and the option to compute concentrations at arbitrary times (useful for C_τ in SD). Before we needed a workaround.

❝ Of course, the structure of the curve should be more complicated and there could be several intersections...

Exactly. See here, there, and my example above.

❝ 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?

IMHO, in Phoenix/WinNonlin impossible. In Phoenix/NLME doable since PML (Phoenix Modeling Language) offers the required features to loop through the data.
May I ask: Why do you need the intersections? Curiosity (aka “nice to know”)?

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

Nice try! As you rightly observed: Does not work for multiple intersections and/or >1 subject.

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


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

Complete thread:

• Calculation of time above MIC Aceto81 2008-06-26 16:31 
  • Calculation of time above MIC Helmut 2008-06-26 18:58
    • Calculation of time above MIC Aceto81 2008-06-26 21:50
      • Calculation of time above MIC Helmut 2008-06-27 00:18
      • Calculation of time above MIC Helmut 2008-06-29 02:24
        • Calculation of time above MIC Aceto81 2008-06-30 15:50
          • Therapeutic Occupancy Time / MEC Helmut 2008-06-30 16:45
    • Time above MIC (WinNonlin 5.2.1) Helmut 2008-08-08 20:38
      • Time above MIC (WinNonlin 5.2.1) Aceto81 2008-08-12 09:56
        • Time above MIC (WinNonlin 5.2.1) Helmut 2008-08-12 12:32
          • Time above MIC (R function) Aceto81 2008-08-13 11:19
            • Time above MIC (R function) Helmut 2008-08-13 13:18
              • Time above MIC (R function) Aceto81 2008-08-13 15:35
          • Phoenix-WinNonlin 6.0 released 29 May 2009 SDavis 2009-06-04 10:55
            • Phoenix-WinNonlin 6.0 Helmut 2009-06-04 11:57
              • Phoenix-WinNonlin 6.0 - introductory webinars SDavis 2009-06-04 18:50
                • Phoenix-WinNonlin 6.0 - introductory webinars Helmut 2009-06-04 23:40
      • TimeLow Astea 2017-10-28 22:15
        • PHX/WNL 8.0 vs. previous releases Helmut 2017-10-28 23:20
          • PHX/WNL 8.0 vs. previous releases Astea 2017-10-28 23:49
        • Occupancy, Half Value Duration, Plateau Time in Phoenix/WinNonlin 8 Helmut 2017-10-30 13:18
          • Occupancy, Half Value Duration, Plateau Time in Phoenix/WinNonlin 8 Astea 2017-10-31 01:12
            • IntersectionsHelmut 2017-10-31 12:32
              • nobody needs it... Astea 2017-10-31 18:24