Bioequivalence and Bioavailability Forum

❝ Should I just need to design the sampling time to 72hr or need to longer than 72hr?

❝ If I just sampling for 72hr， how can I prove the drug is a long half life drug?

• Up to 72hrs
  
• You will perhaps see some subjects do not display much of an elimination phase within the sampling time span. It is actually not easy to define quantitatively how you deliver the proof of subjects not entering the elimination phase or not doing it much. The thinking is of course that you compare AUC72 to AUCinf but since AUCinf is not always estimated due to missing elimination constants direct numerical gymnastics on AUCinf and AUC72 isn't going to be possible in all cases.
  There are generally two explanations for not having an elimination constant: Too short sampling time or a lot of scatter.
  So, depending on how long the elimination phase is you may or not have have AUCinf for some subjects. As long as you can argue it isn't a scatter issue you will then be fine for those, and for the rest it may come down to a plain comparison of the AUCs.