Assessing Reliability, Confidence, And Inter/Intra Batch Variation Uncertainties In PPQ Sample Size Selection

Determining the number of process performance qualification (PPQ) runs is essential in order to ensure you can provide sufficient statistical confidence of quality both within a batch and between batches, as described in the FDA’s process validation guidance. The confidence level selected can be based on risk analysis as it relates to the particular attribute under examination.

The tolerance interval (TI) method and the process capability (PpK) method, two statistical methodologies for calculating the necessary number of PPQ runs, both methods produce PPQ results with an acceptable statistical confidence and without some of the limitations inherent to other statistical approaches. Examine the procedures and benefits of these two approaches and how new therapeutic technologies are requiring a risk-based approach to calculate the number of PPQ runs to meet predefined specifications at a predefined statistical confidence.