Bioequivalence and Bioavailability Forum

Dear Jay,

❝ The halflife of Proton pump inhibitors is around 2 hrs, so 10 half life sums up to 20 hrs. So for BE Study considering the washout as 1-2 days would be acceptable?

This is elimination half life we are talking about not the half life of drug action.

❝ As PPI influence the acid level by inhibiting the acid release from parietal cells, so would this effect the absorption of the drug if washout is kept 1-2 days.

To understand this you need to look for few things as

1. Exact mechanism of action of PPIs
   
2. Regeneration rate of Proton pumps
   
3. At a given point of time how many proton pumps are active/regenerating/nascent phase
   
4. Time for which pH is above 4.5 (for few PPIs it has been more than 18 hrs)

Look for the points I shared and then you will be able to understand why washout of 1-2 day is a really bad idea.


Hope this will help.