Bioequivalence and Bioavailability Forum

Dear M,

please look here first.

❝ The US high fat breakfast as required by the FDA in fed studies is quite a

❝ stomach-full for us Europeans (female study subjects in particular find it

❝ hard to finish).

Full ACK. See also this post.

❝ How much of the breakfast must be consumed to be eligible? Is it

❝ acceptable to eat say 60% or 75%?

I've seen protocols were the amount of food (of course not the composition) was different for males/females. All these studies were European ones (not used in NDA/ANDAs).
If you run into the situation that a volunteer capitulated in the first period - you may give it a try: write down a protocol deviation and serve a (reduced) amount in the second period. This is only valid for a BE study in the fed state. If happening in the second period or a fed/fasting study, you are out of luck.

❝ How important is it to weigh each constituent (bacon, waffles etc.)?

I wouldn't do that. You would end up with messy scales, etc. There's a lot of literature about the composition of food out there (just check a pack of toast in the local supermarket - there's a lot printed on it). Even the old Geigy tables were quite informative. Just document what you have served in a simple way plus the breakdown according to FDA's guideline (fat, carbohydrates, protein)...

❝ I have heard that the FDA can be quite strict on this.

On what? Sticking to 'their' breakfast? Yes. Weighing ingredients - haven't heard of.

I once established a European substitute (until FDA's prestidigitation with 'viscosity' came in), and found it a little bit difficult to get an idea about FDA's specifications of their 'test meal', e.g.,
  2 strips of bacon (estimated with 3 g each)
  2 slices of toast (estimated with 37.5 g)
  butter (who much? estimated with 20 g)
Using energy contents for 1 g of fat (38.9 kJ) and protein/carbohydrate (17.2 kJ) I ended up with
12% (128 kcal) of protein, 29% (308 kcal) of carbohydrate, and 59% (631 kcal) of fat. So even FDA's 'test meal' does not meet their own spec's (150, 250, 500-600)...