Ionic Impurities in Drug Products – USP Proposes New Ion Chromatography Method

One of the main goals of the USP monograph modernization initiative is to replace non-specific methods with highly selective and sensitive instrumental analysis methods. Based on a joint project with Metrohm, the USP proposes a new ion chromatography method for chloride and sulfate detection in drug substances, potassium carbonate, and potassium bicarbonate.

Chloride and sulfate are common impurities present in drug substances and drug products. Current limit tests as per USP general chapter are based on turbidity and/or visual comparison methods. Both methods lack specificity and fail the requirements of data integrity.

Addressing these shortcomings, the USP proposes a selective and sensitive ion chromatography method for chloride and sulfate detection in drug substances, potassium carbonate, and potassium bicarbonate. The method is described in a free technical poster.