Bioequivalence and Bioavailability Forum

Dear Gary!

❝ I want to reformulate as my company has submitted this to regulatory authorities and they have asked the reasons for overages.

Do I get you right: the test used in the BE-study was intentionally formulated to a content 104%? If yes, this was a bad idea. If it was formulated to 100% and only the actual content (analysis of the final product) came out with 104%, nothing to worry about. Please clarify.

❝ Moreover my company wants to reformulate it without overage and with only 100%API.

Just out of couriosity: why was the product formulated to 104%?

❝ I want to know if it is possible to avoid bioequivalence study of tablet if we reduce % of API and how much percentage of variability is allowed.

What BCS Class is your drug in? Should be possible for Classes I & III, and tricky for Class II - impossible for Class IV.

❝ please tell if there is any european or ICH guideline to this issue.

Have a look at the relevant BE-Guidelines here (BA/BE 2001, Q&A document 2006, BE-draft 2008).
There are no ICH-guidelines on BE (and no intentions to come up with one).