Bioequivalence and Bioavailability Forum

Hi Venu!

❝ In BA/BE studies, why only 2x2 crossover design noncompartmental models are used in most of the pilot and pivotal studies?

Not only 2x2 cross-overs, but also 4x4, 6x3, replicate designs, parallel groups,...

❝ When can you use the compartmental models in the BA/BE stuides?

Additional to NCA you are free to perform any type of evaluation you want.

❝ Does the use of these compartmental models depend on the nature of the generic drugs.

No.

❝ Please if you could provide more information in detail regarding the questions mentioned above.

For details (especially why compartmental models are not used in BA/BE) see Helmut's post.

Hi Venu,

2x2 cross over design is a standard design. Definitely this is not the only design for BA/BE studies. You can also use replicate designs if you can justify its use. For cross over studies there are many designs.

Yes, you can use compartment models. The only reason why the guidelines insist on non-compartment models is, to use compartment models you need good expertise in pharmacokinetic principles and one should know exactly how and when to use compartmental models. One should also know then how many data points are to be used in the log-linear segment in the elimination phase based on the number of compartments one uses. This is bit complicated to non-pharmacokineticians (most CROs employ nono-pharmacokineticians to do data modeling).

Dr. Shiv

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Edit: Full quote removed. [HS]