Free and total analyte [Bioanalytics]

posted by Mithu – India, 2019-07-23 13:32 (356 d 00:00 ago) – Posting: # 20437
Views: 1,820

» Please define your terms.

Free analyte available in systemic Vs. Conjugated drug.

» Are you referring by “free” to the fraction which is not protein-bound?


Here i am talking about Scopolamine Patch 1/72 hrs. The label is talking about free as well as total Scopolamine (free + conjugated analyte). SBOA contains study which was approved in 2015 does not contain any bifurcation of total or free Scopolamine measurement.

As per my understanding, when half life is less i.e. <10 hrs and there is no major protein bounding, i believe what we are measuring is beyond the category of free or conjugated. As i believe, when there is a higher amount of protein binding, half life would be also high i.e. >20 hrs and more and clear information about drug conjugation should be defined.

please correct me if my understanding is not correct.

In such cases, where we have to measure free and total analyte, analytical methodology would also be different and must contain different extraction method to detect free as well as conjugated analyte.

Here label says metabolize profile of Scopolamine is not fully characterized.

Hope i could put my point in current manner and properly.



Complete thread:

 Admin contact
20,824 posts in 4,357 threads, 1,449 registered users;
online 19 (1 registered, 18 guests [including 6 identified bots]).
Forum time: 13:32 CEST (Europe/Vienna)

The analysis of variance is not a mathematical theorem,
but rather a convenient method of arranging the arithmetic.    R.A. Fisher

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