Retrospective Validation - Types of Process Validation

-Retrospective validation involve based on the available data  and the examination of past experience of production.

-Retrospective validation is performed when  established processes that have been used without significant changes to API quality due to changes in raw materials, equipment, systems, facilities, or the production process. 

-As per ICH Q7 guideline This validation approach may be used where:

Critical quality attributes and critical process parameters have been identified;

Appropriate in-process acceptance criteria and controls have been established; 

-There have not been significant process/product failures attributable to causes other than operator error or equipment failures unrelated to equipment suitability; and

-Impurity profiles have been established for the existing API. 

-Batches selected for retrospective validation should be representative of all batches made during the review period, including any batches that failed to meet specifications, and should be sufficient in number to demonstrate process consistency. Retained samples can be tested to obtain data to retrospectively validate the process.

-Retrospective validation is never applied to new processes or products. It may be considered in special circumstances only.

-Now a day this concept is rarely used.