Bench Boost by Inorganic Ventures

Send us Fan MailThis week Mike and Ashley explain the J value used in pharmaceutical elemental impurity testing to relate typical ICP concentration units to permitted daily exposure (PDE) limits reported in micrograms per day under USP <232> and ICH Q3D. They describe how J value accounts for both sample dilution factor and maximum daily dose, making results comparable to PDE requirements. They recommend preparing method standards at PDE limits for the relevant administration route and diluting to match the J calculation for method validation.

Send us Fan MailThis week Mike & Ashley review the standardized methods for elemental impurity analysis in pharmaceuticals: ICH Q3D, USP <232>, and USP <233>. ICH Q3D provides guidelines for testing up to 24 elements and emphasizes risk assessment but not detailed testing calculations; USP <232> sets elemental impurity limits; and USP <233> addresses sample preparation and analysis and relies on ICH Q3D concepts such as “J” concentrations (to be covered next week). They explain risk assessment factors (element, route of administration, intentional addition, and screened materials) and outline element classes. They also discuss sample types (APIs, drug products, excipients) and how early screening can reduce final testing needs.