Metal impurities are introduced into pharmaceutical products and dietary supplements from raw materials, catalysts, equipment and the environment. World regulatory agencies are finalizing limits for elemental impurities based on their potential toxicity (ICH Q3D and USP<232>). Minimally, arsenic, cadmium, lead, and mercury will be targeted in a risk-based strategy.
R.D. Laboratories has significant expertise and a variety of specialized equipment to assist with inorganic impurity testing.
We routinely use the GBC Avanta atomic absorption spectrometer for very specific and quantitative analysis for a variety of elements. Flame vaporization, hydride generation, cold vapor, and electrothermal atomization methods provide parts-per-billion level detection. We use a hydride generator for the determination of mercury by cold vapor and analysis of arsenic, selenium and other hydride forming elements. Our GBC GF3000 graphite furnace performs extremely sensitive trace elemental analyses of elements other than those measurable by cold vapor.
The current Heavy Metals test USP <231> lacks specificity and the ability to accurately quantify individual inorganic impurities. The USP is abandoning this subjective wet chemical method in favor of a sophisticated quantitative instrumental technique. Elemental Impurities (USP<233>) proposes the use of Inductively Coupled Plasma with Optical Emission Spectroscopy (ICP-OES) or Mass Spectrometry (ICP-MS). The USP is expected to require metal testing utilizing these techniques in May 2014.
R.D. Laboratories believes that the ICP-MS offers significant sensitivity advantages over ICP-OES and has qualified a Thermo Scientific X SERIES 2 ICP-MS. This system offers accurate multi element determinations to part-per-billion levels with a wide linear range. For samples that are not easily solubilized we utilize a CEM Discover SP-D closed-vessel microwave digestion system. The ICP-MS system couples to chromatographic or electrophoretic equipment if speciation is required.