BioPharm International-03-10-2005

Analytical method validation (AMV) is required in the biopharmaceutical industry for all methods used to test final containers (release and stability testing), raw materials, in-process materials, and excipients. 1 AMV is also required for test methods that are used to validate the process prior to process validation. This article reviews current regulatory guidelines and the critical elements of analytical method development (AMD) that should be finalized before starting AMV.

Synthetic drugs can be well characterized by established analytical methods. Biologics on the other hand are complex, high-molecular-weight products, and analytical methods have limited abilities to completely characterize them and their impurity profiles. Regulation of biologics includes not only final product characterization but also characterization and controls on raw materials and the manufacturing process.

Many types of equipment in both manufacturing and laboratory areas are critical to a properly functioning pharmaceutical process. The validation of laboratory equipment is not as clearly defined as the validation of equipment used directly in the production of pharmaceutical products, which requires thorough validation in almost all situations.

The variety of microbiological tests makes it difficult, if not impossible, to prescribe a single, comprehensive method for validating all types of tests. By their very nature, microbiological tests possess properties that make them different from chemical tests. Consequently, the well-known procedures for validating chemical tests are not appropriate for many microbiological tests. Yet, it is necessary to validate microbiological tests if they are to be useful for controlling the quality of drug products and devices. Test-method validation provides assurance that a method is suitable for its intended use. Given this definition, any rational company would want to be sure that its methods are validated.

The purpose of design validation is to demonstrate that a product performs as intended. The usual route to this goal is showing that every item on the specification has been achieved, but it is not an easy path. The specification itself can create difficulty if it includes statements like "as long as possible" or the real horror "to be decided." Verification tests can reveal so many problems that the design must change to such an extent that earlier tests are no longer relevant. And there is also the practical difficulty of obtaining sufficient samples to test when the manufacturing engineers have not completed their standard operating procedures, the product design is not fixed yet, the component suppliers are late, and the marketing department has taken all the samples to show to prospective customers.