Bioequivalence and Bioavailability Forum

Dear all,
I just reviewed the FDA recommendations for a specific drug product with a long elimination half life and I am wondering why in the suggested parallel design study (or cross-over study) the administered single dose should be 3x1 capsule. There is only one strength available and the recommended dose in patients is 1x1 capsule daily as this represents the therapeutic plateau. The pharmacokinetics are doseproportional over a very wide range, the lowest dose investigated was 4 times lower than the actual dose. So the sensitivity of the bioanalytical method could not be the reason for dosing three capsules. The absorption is slow and extensive, bioavailability is nearly 100%. Do you have any idea?
If I use the FDA recommended study design for European submission what could be a possible reason for rejection? Is a BE study with dosing 3x1 capsule less or more sensitiv to detect possible differences in formulation than 1x1 capsule?
Looking forward to your reply.
Thanks in advance
Dan