Bioequivalence and Bioavailability Forum • Sulindac Metabolites

Noha Abdeljawad
☆

Cairo, Egypt,
2013-02-26 10:08
(4868 d 03:17 ago)

Posting: # 10119
Views: 4,908

Sulindac Metabolites [Regulatives / Guidelines]

Hello Everyone,

Sulindac sulfoxide is a prodrug with no pharmacological activity. It is water-soluble and readily absorbed from the intestine then undergoes two major biotransformation reactions: a reversible reduction into a Sulfide which is pharmacologically active and an irreversible oxidation into a Sulfone.

My question is, in a bioequivalence study comparing sulindac tablet formulations, which analytes will the 90% CI be based on; the parent compound and the sulfide (active metabolite) or the sulfide only or the parent compound only? I couldn’t find an FDA guidance paper for sulindac.

—
Best Regards
Noha Abdeljawad

Helmut
★★★

Vienna, Austria,
2013-02-26 16:33
(4867 d 20:51 ago)

@ Noha Abdeljawad
Posting: # 10124
Views: 4,054

Which agency?

Post reply

Dear Noha,

which regulatory agency is your “target”? Examples:

FDA
“Measurement of a metabolite may be preferred when parent drug levels are too low to allow reliable analytical measurement in blood, plasma, or serum for an adequate length of time. We recommend that the metabolite data obtained from these studies be subject to a confidence interval approach for BE demonstration.”
EMA
“[…] for inactive prodrugs, demonstration of bioequivalence for parent compound is recommended. The active metabolite does not need to be measured. However, some pro-drugs may have low plasma concentrations and be quickly eliminated resulting in difficulties in demonstrating bioequivalence for parent compound. In this situation it is acceptable to demonstrate bioequivalence for the main active metabolite without measurement of parent compound. In the context of this guideline, a parent compound can be considered to be an inactive pro-drug if it has no or very low contribution to clinical efficacy.”
It seems that sulindac sulfoxide is BCS class I (highly soluble, highly permeable). Maybe a biowaiver is an alternative.
EDA
“The measurement of concentrations of therapeutically active metabolite is acceptable if the substance studied is a pro-drug.”

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz

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

Noha Abdeljawad ☆ Cairo, Egypt, 2013-03-05 12:11 (4861 d 01:13 ago) @ Helmut Posting: # 10152 Views: 3,834	Which agency? Post reply
	According to the EDA Thanks, Helmut — Best Regards Noha Abdeljawad