Bioequivalence and Bioavailability Forum

Hello everyone. Hope the weather is better where you are than where I am.

One more question if you will (with subquestions, potentially), before we retire this thread. I think its obvious I'm curious about oral solutions and BCS based biowaivers, so no need form me to be sly. So, if anyone has experience with this or wants to comment on my thinking, please do and I will be appreciative.

1. The EU BE guideline says: In those cases where the test product is an oral solution which is intended to be bioequivalent to another immediated release oral dosage form, bioequivalence studies are required.

2. Appendix III on BCS based biowaivers states: The concept is applicable to immediate release, solid pharmaceutical products for oral administration and systemic action having the same pharmaceutical form.

Fair enough on point 1 (oral versus solid); standard BE requirement stated without taking into account the BCS classification of the products. Now point 2 seems to indicate exclusivity to solid dosage forms when compared to a product that has the same pharmaceutical form. But we also know from the BE guideline that various immediate-release oral pharmaceutical forms shall be considered to be one and the same pharmaceutical form (except for ODT unless you can rule out buccal absorption, etc).

Am I correct in assuming that the guideline seems to imply that a solid dosage form (T) can obtain a BCS-based biowaiver versus an oral solution (R), but somehow an oral solution claiming a BCS-based biowaiver versus a tablet is not covered?

Personally, I think I have room to justify trying to submit a BCS-based biowaiver for an oral solution when the only option is a tablet reference product, both from a regulatory viewpoint and a scientific one. Or should I just up my thorazine dose? Of course all this hypothesizing is moot if anyone of you already has experience with this situation. Thanks in advance.