Bioequivalence and Bioavailability Forum

Hi,

❝ What is the impact on the study out come(Bio-analytical results) for a BA/BE study in the following case.

❝

❝ Case1: If i use 3ml K3EDTA vacutainer (if i don't have 2ml vacutainer) for 2ml sample?

How would you know that you collected 2 mL? Eyeball it? You might not have enough plasma sample for assay repeats. It depends no how much plasma the lab needs.

John

Dear akinapally
If you use 3ml instead of 2ml K3EDTA vacutainer then you will have a variability in full blood and consequently in plasma volume. The outcome of the study, i.e. the decision on bioequivalence is not affected as long as the analytical method provides valid results.
Kind regards
Dan

Dear Akinapally,

Problems have been described with partially filled EDTA tubes when using immunoassays. Have a look at this review:

Raffick A.R. Bowen , Glen L. Hortin, Gyorgy Csako, et al.
Impact of blood collection devices on clinical chemistry assays
Clinical Biochemistry 43 (2010) 4–25

Regards
Ohlbe

Hello Akinapally,

❝ What is the impact on the study out come(Bio-analytical results) for a BA/BE study in the following case.

❝

❝ Case1: If i use 3ml K3EDTA vacutainer (if i don't have 2ml vacutainer) for 2ml sample?

If you are able to somehow collect 2 ml into a 3 ml tube:
The plasma you process may contain 50% more K3EDTA, this change could at least in theory be significant to the downstream processing of the sample. I would advise that this phenomenon be evaluated e.g. as a kind of ruggedness test in the bioanalytical validation.

If you collect 3 ml (or what could subjectively by others than yourself be considered a quantitatively larger amount than 2 ml) into a 3 ml tube:
While the bioanalytical result may not be affected per se, I'd have some potential worry since the protocol would usually specify that you are collecting 2 ml samples and XYZ ml in total per period. Collecting more may be a protocol violation.