HVD Pilot: 3 candidates, 1 reference [Design Issues]
❝ Can anyone please suggest the study design for pilot study with three test formulations and one reference formulation for highly variable product.
More info about the purpose would be great. But in the absence of any more detail, I would go for a 5-period, 4- treatment, n-sequence BE design, where n (the number of sequences, and thus their nature) depends a little bit on how cool you are (I would not care about bias, but I am rather alone in this regard, I think) and your sample size. The sample size is a little dependent on what you can tell about the expected intra-subject variability. You need to be a little more detailed than just mentioning it is highly variable.
I usually do not recommend to use a pilot for evaluation if one of a number of Test treatments is a potential match for the Ref. This is because of the uncertainity. Some weirdo published a paper about this phenomenon, I think.
Pass or fail!