"In my opinion, using trending data to complement—or even shorten—validation studies should not be an issue, provided it's done appropriately. The primary goal of a validation study is to provide evidence of method performance. This involves formulating a hypothesis in the form of predefined acceptance criteria and then generating experimental data to test that hypothesis.

Trending results, in principle, align with this scientific mindset. They offer real-world performance data that can support or reinforce conclusions drawn from formal validation experiments. However, it's essential that such trending data be generated under controlled conditions—using qualified personnel, qualified instruments, and within a qualified system.

This is particularly relevant when considering trending data collected before formal method validation. In many cases, these earlier data points were obtained under less controlled or variable conditions, which limits their suitability for use as validation evidence. As a result, such data must be critically assessed for relevance and reliability.

That said, the practical reality is that trending typically occurs after method validation. This makes its timing less suitable for replacing validation studies but highly relevant for complementing them. In practice, trending data is particularly valuable for demonstrating ongoing method performance over time, and for confirming that analytical procedures remain in control after validation."

Learn more from Dr. Lars Geurink by viewing his presentation "Analytical Procedure Control Strategy (ACPS)" during the Expert Forum: Overcoming key challenges in understanding and implementing guideline ICH Q14 for Analytical Procedure Development