for 200 doses, it's saying after priming, we want the information in terms of dose content uniformity at the first primed dose, somewhere in the middle, and then at the 200th dose. So the goal there is to look at variability within the container. So that's why beginning, middle and end life stages is included.
The test calls for that information to be conducted on each of three containers. That's a total of nine determinations at tier 1, and similar to the prior recommendation, not more than one of the nine determinations shall lie outside of 80 to 120 percent of label claim, zero tolerance criterion, 0 outside of 75 to 125 percent of label claim, and again the means at each of the beginning, middle and end are not outside of 85 to 115.
This test simply indicates that this DCU through container life for the multi-dose products applies also in its essential characteristics to dry powder inhalers and also to nasal sprays.
Now, there have been a number of publications talking about parametric tolerance interval tests for various dosage forms, and a parametric tolerance interval approach takes the general form of the criterion indicated