Bioequivalence and Bioavailability Forum

Hi Detlew,

Let me irritate you a bit this morning

❝ Boys!

❝

❝ From my vacation: What is your problem ?

❝

❝ CVfromCI() gives you the CV for the difference T vs. R.

❝ This is some pooled value of the intra-subject variances of T and R ¹⁾.

❝ So don't expect to get a value comparable to s²_wR!

If the Intra-CV derived from the pool'd variance is higher/lower than the intra-CV derived from the S²wR, then could one suggest that the difference is attributed to the test formulation (meaning test has larger or smaller variability)?

See some interesting data below. I ran Proc Mixed (FDA progesterone HVD SAS code) to obtain the reference residual variance and computed the corresponding intra-cv. I then used R to back-calculate the intra-cv from the 90% CI generated by Proc Mixed (first column data).
Formulation 1                  
         Pool'd Var      Ref      Ref      
         Intra CV %      Res Var  Intra-CV%   Δ Intra-CV(Pool-Ref)
Cmax        64.94        0.3040   59.60           5.33
AUCt        74.18        0.3006   59.22           14.96
               
Formulaton 2                  
         Pool'd Var      Ref      Ref      
         Intra CV %      Res Var  Intra-CV%   Δ Intra-CV(Pool-Ref)
Cmax        87.25        0.3268      62.17        25.08
AUCt        68.08        0.2641      54.98        13.10


Thanks
John