Philosophy and goals of validation for biotech products and the relevance of scale.

A model for validation of viral clearances in Biopharmaceutical processes is developed from an analysis of validation of terminal sterilization processes. The model develops the role for small-scale experiments in the validation of large-scale production processes. The steps for process validation are: identify or discover the basic general physical, chemical, or biological laws governing the process; identify the critical process control parameters for the specific application under investigation; and demonstrate the ability of the production equipment to maintain critical parameters with specified limits. For concurrent validation, this final step is seen as equivalent to demonstrating that a scaled-down model experiment is an appropriate representation of the production process.