Bioequivalence and Bioavailability Forum

Main page Policy/Terms of Use Abbreviations Latest Posts

 Log-in |  Register |  Search

Back to the forum  Query: 2017-10-19 20:09 CEST (UTC+2h)

2010-09-22 17:28

Posting: # 5931
Views: 2,899

 Unconjugated and total in BE assessment [Regulatives / Guidelines]


First time user, very nice and useful website.
I was wondering if someone might be able to offer advice on the need to present unconjugated and total (unconjugated+conjugated) data for EU submission, for compounds such as ursodeoxycholic acid or naloxone, in BE trials. In the case it is, would the expectation be to be within 80-125% limits for all analytes, or would certain analytes be required for supportive information only? For ursodiol (ursodeoxylic acid), FDA clearly requires demonstration of BE on total and unconjugated drug, but the EMA guidance doesn't address conjugation.

Thanks in advance,


2013-12-19 16:42

@ durenmatt
Posting: # 12080
Views: 1,666

 Baseline corrected and/ or uncorrected Ursodiol

Dear forum members,

For Ursodiol capsules FDA recommends:

Bioequivalence based on (90% CI): Baseline corrected and uncorrected (i) unconjugated ursodiol and (ii) total (conjugated and unconjugated) ursodiol.

However we intend to submit to MHRA. Could someone please advise if MHRA also insists on baseline corrected as well as uncorrected data, or only baseline corrected data will be sufficient to show BE.

Thank you,
Kind regards,
Mauricio Sampaio

2017-04-05 18:52

@ durenmatt
Posting: # 17229
Views: 657

 Ursodeoxycholic acid: Unconjugated and total in BE assessment

Dear members,

according the question above (7 years ago), I am asking to myself and you if anybody to have a response on the need to present unconjugated and total (unconjugated + conjugated) data for ursodeoxycholic acid, to prove the bioequivalence between two formulation (FDA requires demonstration of BE on total and unconjugated drug)? :confused:

If the focus of the bioequivalence test is identify significant differences from formulation, what is the sense to quantify tauroursodeoxycholic acid and glycoursodeoxycholic acid ? :confused: The measurement of these metabolites in human plasma may be helpful in understanding the metabolism of the parent compound, but it is not applied to understand the differences between two formulation. Both are from physiological limitation and not from galenic limitation.

The quantification only Ursodiol acid (the parent compound unconjugated) is not enough?:confused:

If any members could answer me, I really appreciate.
Back to the forum Activity
 Thread view
Bioequivalence and Bioavailability Forum | Admin contact
17,395 Posts in 3,726 Threads, 1,073 registered users;
29 users online (0 registered, 29 guests).

No investigation can strictly be called scientific
unless it admits of mathematical demonstration.    Leonardo da Vinci

BEBAC Ing. Helmut Schütz