CVintra #79 [Power / Sample Size]
Dear shripushpa!
in the future please
search the forum before posting.
No idea. For sure HVD (≥30%) – that’s why FDA published their guidance allowing scaling for both AUC and Cmax. Les Benet gave one example (slide 9) with CVs of 61% for AUC and 98% for Cmax.

in the future please
search the forum before posting.- CVintra is an estimate. For it’s calculation from ANOVA’s residual variance see e.g. this post.
- Generally none. CVintra is only important in study planning, with one exception: Reference-scaled BE for highly variable drugs / drug products (HVDs/HVDPs). In some regulations you may scale the acceptance range based on the CV observed in the study (if ≥30%).
- Most important: CVintra varies between studies. Never take anything from the literature as a natural constant. If the same clinical setting + analytical method is used, in my experience CVs of different strenghts do not vary too much. If different dosage forms (or even worse different routes of administration) are compared it might be a nightmare.
CVs of diclofenac’s AUCs (22 studies): solution 7.47%, effervescent tablet 11.2%, rectal 14.7%, suspension 17.6%, gastric resistant 17.7%, dermal 32.7%.
❝ & also progesterone intra subject cv value.
No idea. For sure HVD (≥30%) – that’s why FDA published their guidance allowing scaling for both AUC and Cmax. Les Benet gave one example (slide 9) with CVs of 61% for AUC and 98% for Cmax.

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна!![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png)
Helmut Schütz
![[image]](https://static.bebac.at/img/CC by.png)
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png)
Helmut Schütz
![[image]](https://static.bebac.at/img/CC by.png)
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Complete thread:
- Intrasubject cv value shripushpa 2011-12-30 12:48
- CVintra #79Helmut 2011-12-30 14:51
