Method development on automated sample preparation system for content uniformity and assay testing in a product with multiple APIs and new strategy for quick development and application.

Automation of analytical sample preparation and testing is always attractive due to its high efficiency and continuous operation, but it can also be very challenging due to the operational complexity and method development. Studies focused on method development in automated systems are extremely rare and little has been published on the subject. In this paper, we investigate several unique and advanced aspects of this subject.

Assay of active pharmaceutical ingredients in drug products based on relative response factors: Instrumentation insights and practical considerations.

Relative Response Factors (RRFs) can be used for quantitation of one compound against another and it is widely used for Impurity analysis of pharmaceutical products; however, the application in potency assay is limited. Through an extensive study shown in this paper, it can be concluded that using the "RRF methodology" for potency assay is much more challenging compared to impurity analysis, due to the much tighter criteria required for potency analysis. The effects of instrument settings, which are rarely discussed or recognized in current HPLC analytical method development and quality release testing, are discussed.