**13. Challenges associated with validated methods**

Remediation of validated analytical methods is typically triggered by the need to improve existing methods used for disposition of commercial products. The improvement may be required due to an unacceptable rate of method failures in the GMP environment, lengthy run times, obsolete instruments or consumables, the changing regulatory environment for specifications or stability testing, or for other business reasons.

We anticipate that technological advances will continue to drive analytical methods toward increasing throughput. In this context, it appears that many release methods are destined for change as soon as the product has been approved for commercial use (Apostol and Kelner 2008; Apostol and Kelner 2008). This is due to the fact that it takes more than 10 years to commercialize a biotechnology drug, resulting in significant aging of the methods developed at the conception of the project. Therefore, the industry and regulators will need to continuously adjust strategies to address the issue of old vs. new methods, particularly with respect to how these advances impact product specifications (Apostol, Schofield et al. 2008). Frequently, old methods have to be replaced by methods using newer technologies, creating a significant challenge for the industry in providing demonstration of method equivalency and a corresponding level of validation for the methods.
