in previous releases of PHX/WNL the intersection of the profile with a fixed value was always performed by linear interpolation (increasing concentrations) and by log/linear interpolation (decreasing concentration) – which IMHO, is the method of choice.
This lead to confusion in the past since this method was independent from the selected AUC calculation. Since v8.0 the method observes the chosen AUC-rule.
Calculating the Occupancy Time (time interval where concentrations are at least some limiting value, e.g., the MIC) is trivial. However, the Half Value Duration (HVD, interval where C ≥ 50% Cmax) or the Plateau Time (t75%, interval where C ≥ 75% Cmax) needs two steps.
- Get the subject’s Cmax and calculate the required fraction(s).
- In the final NCA > Therapeutic Response > map the calculated fraction to Lower and Cmax to Upper.
It is not possible to calculate HVD and t75% simultaneously. If you need both, run two NCAs and join their results.
Half Value Duration and Plateau Time.phxproj 1.18MB 296 downloads