Determination of ICH class 1 and class 2A trace elements in Triheptanoin oral liquid for long-chain fatty acid oxidation disorders, an ICP-MS approach

Elemental impurities in pharmaceutical products pose significant safety concerns and are strictly regulated under ICH Q3D (R2) guidelines. This study presents a validated method for the quantitative determination of ICH Class 1 (As, Cd, Hg, Pb) and Class 2A (V, Co, Ni) elemental impurities in Triheptanoin oral liquid, a treatment for Long-Chain Fatty Acid Oxidation Disorders. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was selected due to its exceptional sensitivity, capability for simultaneous multi-element analysis, and low detection limits, making it ideal for trace-level determination and well-suited for meeting regulatory compliance requirements. The permitted daily exposure (PDE) limits were adjusted according to the maximum daily dose of the drug to ensure accurate risk assessment. Sample preparation was performed using a high-performance microwave-assisted acid digestion method. The method exhibited excellent selectivity, sensitivity, and precision, with detection limits of 0.045 µg g⁻¹ (V), 0.023 µg g⁻¹ (Co), 0.090 µg g⁻¹ (Ni), 0.007 µg g⁻¹ (As), 0.002 µg g⁻¹ (Cd), 0.014 µg g⁻¹ (Hg), and 0.002 µg g⁻¹ (Pb), all reported as concentrations in the sample. Strong linearity was achieved (r > 0.9995), and recovery rates ranged from 98.0% to 102.1% across concentration levels (n = 3), demonstrating high accuracy and consistency. Precision, expressed as %RSD, was below 3.2% for all elements, with specific values of 0.8% (V), 2.7% (Co), 1.1% (Ni), 1.4% (As), 2.4% (Cd), 1.4% (Hg), and 3.2% (Pb). The method demonstrated robustness with overall %RSD not more than 5%. These results support the method’s suitability for routine quality control and regulatory compliance, providing pharmaceutical manufacturers with a reliable tool for ensuring product safety and facilitating market authorization.