Bioequivalence and Bioavailability Forum

Dear SriRam,

nice image – where does it come from?

❝ 1. How does WinNonlin report bioavailability? (Parameters considered)

See the manual of version 4.1, pp234–244. Note that the current version is Phoenix/WinNonlin 6.3. You can get a free trial-license from Pharsight. To calculate the bioavailability use the bioequivalence wizard, setting the iv dose as reference and po as test. For NDAs generally a 95% confidence interval (rather than the 90% CI in bioequivalence) is used.

❝ 2. […] the Bioavailability equation (F = DNAUC po / DNAUC iv) Valid for Both Linear Pharmacokinetics (Linear and stationary) and Nonlinear Pharmacokinetics

What does “N” in the equation stand for? If linear pharmacokinetics are applicable the equation of your image is correct (see also here). What do you mean by “stationary”? If linear PK is not established (yet) or PK is known to be nonlinear you cannot use the dose-correction. Administer equal doses and calculate f = AUC_po/AUC_iv or F = 100 × AUC_po/AUC_iv.
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Note the difference between f and F.

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