Free and total analyte [Bioanalytics]

posted by Helmut Homepage – Vienna, Austria, 2019-07-23 11:06  – Posting: # 20436
Views: 437

Hi Mithu,

» please let me know under what condition, free and total analyte needs to be measured in biological fluids?

Please define your terms.

Are you referring by “free” to the fraction which is not protein-bound? Protein-binding is caused by Van-der-Waals forces which will be broken in any sample preparation (SPE, LLE, protein precipitation). Hence, what we measure is always the total analyte. If you are interested in protein-binding (not relevant in BE) go with equilibrium dialysis, ultrafiltration, ultracentrifugation.

Or are you talking about a liposome-encapsulated drug (unencapsulated and encapsulated fractions)? The EMA and the FDA require both (examples: EMA, FDA*).



Cheers,
Helmut Schütz
[image]

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

Complete thread:

Activity
 Mix view
Bioequivalence and Bioavailability Forum |  Admin contact
19,688 posts in 4,178 threads, 1,353 registered users;
online 8 (0 registered, 8 guests [including 5 identified bots]).
Forum time (Europe/Vienna): 21:07 CEST

Power. That which statisticians are always calculating
but never have.    Stephen Senn

The BIOEQUIVALENCE / BIOAVAILABILITY FORUM is hosted by
BEBAC Ing. Helmut Schütz
HTML5