Significant difference in Cmax of Reference drug product [Study As­sess­ment]

posted by Helmut Homepage – Vienna, Austria, 2021-08-17 13:57 (472 d 10:01 ago) – Posting: # 22521
Views: 1,460

Hi Mehul,

❝ Can anybody please tell what may be the probable reasons behind significant (more than 20%) difference in mean Cmax concentration of Reference product of a same batch number in two different studies conducted at same CRO and on the similar kind of population but different sample size?


I guess you had also the same batch of the test? Was the AUC different as well?

❝ Is it correct to compare and expect Reference product's behavior same for all repeated studies?


A few reference products (dasatinib is an infamous example) show extreme batch-to-batch variability. However, generally batches are expected to be similar.
You could compare the references of the two studies as a paired design (assuming to period effects). For a quick estimate calculate \(\small{\widehat{PE}=PE_1/PE_2}\), with \(\small{PE_1=\frac{T}{R_1}}\) and \(\small{PE_2=\frac{T}{R_2}}\), where \(\small{R_1}\) and \(\small{PE_1=\frac{T}{R_2}}\) are the reference batches of the two studies.

❝ […] Can 6 months old (frozen) samples yield significant different results as compared to freshly analyzed study samples?


If long term storage was validated for this duration, no.

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz
[image]

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

Complete thread:

UA Flag
Activity
 Admin contact
22,423 posts in 4,694 threads, 1,600 registered users;
10 visitors (1 registered, 9 guests [including 6 identified bots]).
Forum time: 22:58 CET (Europe/Vienna)

The rise of biometry in this 20th century,
like that of geometry in the 3rd century before Christ,
seems to mark out one of the great ages or critical periods
in the advance of the human understanding.    R.A. Fisher

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5