Eye drops are commonly used medications which are available both over-the-counter and as prescriptions in various forms. Because eye drops are classified as a parenteral medication and have relatively large daily doses, the inorganic components in eye drops must be present at low concentrations. As a result, ICP-MS is the most appropriate technique for the determination of trace elements in eye drops.
The International Conference on Harmonization Guideline for Elemental Impurities Q3D (ICH Q3D) has established maximum permitted daily exposure limits for elemental impurities in pharmaceutical products. This work discusses the sample preparation and analysis of Class 1, 2, and 3 elements in a variety of eye drops with the NexION ICP-MS, following the criteria defined in ICH Q3D. The developed methodology (both sample preparation and analytical) demonstrates both accuracy and stability.