The FDA has published a Q&A document entitled "How does the FDA interpret the regulations (21 CFR Part 211) regarding the establishment of expiry dating for chemicals, reagents, solutions, and solvents?" - including mobile phases.
"Reagents, and standard solutions" - referenced in cGMP's paragraph 211.194 - are actually meant, including laboratory chemicals like solvents and mobile phases, dry chemicals like salts or primary standards and solutions like buffers, acids and bases, whether purchased or self-prepared in the laboratory.
If the manufacturer suggests an expiry date, that date should be followed. The FDA expects an assessment to be performed for purchased laboratory reagents without expiry date indicated by the manufacturer. For example, literature review of that specific chemical's or chemical family's stability may be acceptable to determine an appropriate "use by" or expiry date.
For in-house prepared solutions (like as mobile phases or other non-quantitative solutions), the FDA expects an assessment to be carried out, too.
However, the FDA requires formal stability studies to be performed to determine an appropriate expiry for in-house prepared solutions used for quantitative analysis in assay or impurity testing. According to ICH Q2B, stability of analytical solutions is a typical method variation that should be assessed during "Robustness testings" during validation of an analytical method.
The resulting "use by" or expiry dates should be documented according to an internal SOP.
These requirements also apply for API manufacturers (APIs according to ICH Q7) and their laboratories.
FDA Compliance Officer Brian Belz from the Office of Manufacturing and Product Quality is named as contact person for further information.
Please see the complete Q&A document for further information.Author: