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PPQ Deviation Handling and Success Criteria

1. Purpose and Scope

This article defines how deviations observed during PPQ are managed and how overall success of PPQ is determined.

Focus:

  • how deviations are identified, classified, and evaluated
  • how impact on CPPs, CQAs, and process performance is assessed
  • how deviations influence PPQ conclusions
  • how success criteria are defined and applied

2. Deviation Handling during PPQ

Deviation handling during PPQ defines how unexpected events or results are evaluated to determine their impact on data validity and process performance.

All deviations must be:

  • documented at the time of occurrence
  • investigated to determine root cause
  • assessed for impact on CPPs, CQAs, and data integrity

Evaluation must determine whether the deviation:

  • affects product quality
  • indicates loss of process control
  • compromises representativeness of the batch
  • affects reliability or completeness of data

Based on this assessment:

  • data may be accepted with justification
  • data may be excluded with documented rationale
  • the batch may be included or excluded from PPQ

Exclusion of data or batches must be scientifically justified and must not be used to improve apparent PPQ outcomes.

Deviations that indicate inadequate control strategy, inappropriate CPP limits, or incomplete process understanding require corrective action and may necessitate additional PPQ execution.

3. Identification of Deviations

A deviation is any departure from:

  • approved protocol or procedure
  • defined CPP limits
  • established process conditions
  • expected results or acceptance criteria

Deviations may occur in:

  • process execution
  • parameter control
  • sampling or testing
  • data recording

All deviations must be documented at the time of occurrence.

4. Classification of Deviations

Deviations must be classified based on impact.

4.1 Critical Deviations

Deviations that:

  • affect product quality or patient safety
  • result in CQA failure or potential failure
  • indicate loss of process control

Impact:

  • batch may be rejected from PPQ
  • PPQ may be invalidated

4.2 Major Deviations

Deviations that:

  • affect process performance or data integrity
  • indicate potential weakness in control strategy
  • require investigation and justification

Impact:

  • may affect PPQ conclusions
  • may require additional evaluation or batches

4.3 Minor Deviations

Deviations that:

  • do not affect product quality or process performance
  • are procedural or documentation-related

Impact:

  • do not affect PPQ conclusions when properly justified

5. Investigation and Impact Assessment

All deviations must be investigated to determine:

  • root cause
  • impact on CPP control
  • impact on CQAs
  • impact on data integrity

Evaluation must determine whether:

  • deviation affects process understanding
  • deviation compromises PPQ objectives
  • results remain valid

Investigation must be scientifically justified and documented.

6. Disposition of Affected Data and Batches

Based on impact assessment:

  • data may be accepted
  • data may be excluded with justification
  • batch may be included or excluded from PPQ

Exclusion must be:

  • justified
  • documented
  • not used to artificially improve PPQ outcome

7. Link to Control Strategy

Deviations must be evaluated to determine whether they indicate:

  • inadequate CPP limits
  • insufficient control mechanisms
  • gaps in monitoring or procedures

Where applicable:

  • control strategy must be updated
  • corrective actions must be implemented

8. Definition of Success Criteria

Success criteria must be predefined before PPQ execution.

PPQ is considered successful when:

  • all CQAs meet specifications
  • CPPs remain within defined limits
  • process performance is consistent across batches
  • variability is controlled and predictable
  • no critical or unresolved major deviations remain

9. Evaluation of Overall PPQ Outcome

Final evaluation must consider:

  • all PPQ batches collectively
  • all deviations and their impact
  • consistency of results
  • effectiveness of control strategy

PPQ must not be evaluated on isolated results.

10. Conditions Requiring Additional PPQ or Requalification

Additional PPQ may be required when:

  • critical deviations occur
  • major deviations remain unresolved
  • process variability is inconsistent
  • batch results are not reproducible

Requalification may be required if process understanding is incomplete.

11. Documentation and Justification

All deviation handling and decisions must be:

  • documented
  • traceable
  • scientifically justified

Clear linkage must exist:

Deviation → Investigation → Impact → Decision

12. Summary

Deviation handling ensures that PPQ conclusions are based on valid and reliable data.

Success criteria define whether the process is acceptable for routine manufacturing.

Together, they ensure that:

  • process performance is understood
  • risks are identified and controlled
  • validation conclusions are defensible

This section establishes the final decision framework for PPQ acceptance.