The revalidation process is essential to maintain the validated status of the plant, equipment, manufacturing processes, and computer systems. It should be as important as calibration and maintenance.
Possible reasons for starting the revalidation process include:
- The transfer of a product from one plant to another.
- Changes to the product, the plant, the manufacturing process, the cleaning process, or other changes that could affect product quality.
- The necessity of periodic checking of the validation results.
Note to point 1: For the transfer of a product from one plant to another qualified production plant, it is essential to revalidate the entire manufacturing process in the new plant. It is possible that several new critical or non-critical parameters must be determined. It will also give the working confidence to the persons of new plant.
Note to point 2: In the case of the following changes, revalidation might be necessary:
· Changes in the plant
· Changes in product composition
· Changes in manufacturing processes
· Changes in the packaging materials
· Changes to computer systems
· Changes in the cleaning processes or agents
· Changes which may affect the quality and efficacy of product
The scope of revalidation procedures depends on the extent of the changes and the effect upon the product.
Note to point 3: Periodic revalidation must be done to ensure that no unintentional changes were made and to prove that the results of the previous validation procedures are still valid.
The period of time between the revalidation activities is fixed by the review team. The members of this team should consider the following questions:
A. Are the manufacturing processes sterile, or not?
B. Are the results of the plant (product, performance) expected?
C. Are maintenance and calibrating procedures carried out regularly?
D. What are the critical stages of the processes?
· If the process is sterile then frequency should be less.
· If performance of product is satisfactory then frequency may be increased.
· If maintenance and calibration is carried out regularly then frequency may be increased.
· If process is critical then frequency should be less.