Determination of Elemental Impurities in Antibiotics according to USP 232 and 233 by HR ICP-OES

Determination of Elemental Impurities in Antibiotics according to USP 232 and 233 by HR ICP-OES


  • Post By : Kumar Jeetendra
  • Source: Analytic Jena
  • Date: 08 May, 2019

As of January 2018, pharmaceutical products must comply with specified limits for the allowed exposure to certain trace elemental impurities. The maximum permitted exposure limits and the analytical methods in order to quantify the listed trace elemental impurities are described in the United States Pharmacopeia (USP) chapters Elemental Impurities – Limits[1] and Elemental Impurities - Procedures[2] and are aligned with the International Conference on Harmonization (ICH) Q3D Step 4 guidelines[3].

The described regulations define the list of analytes and the maximum permitted exposure limits taking into account the route of drug administration. The use of closed vessel sample digestion and modern instrumental techniques is also introduced to ensure the accurate recovery and determination of individual target element concentrations. The quantification of trace elemental impurities by ICP instrumentation is becoming a routine task for manufacturers and suppliers of pharmaceuticals. Challenges within this field of application comprise a large variety of sample types with different analyte combinations and target limits. This, in turn, requires ICP instrumentation that can handle a large variety of sample types with varying matrix loading and solvent types (e.g., aqueous or solvent-based) and allows the measurement of a wide concentration range. In this regard, the plasma system needs to be able to handle any sample type without compromising plasma stability and robustness.

The accurate and reliable quantification of trace elementalimpurities also requires a high sensitivity of the system as well as the ability to resolve spectral interferences that are common in ICP-OES. The here described method analyzes cadmium, lead, arsenic, mercury, cobalt, vanadium and nickel in an antibiotic product. The developed method is validated according to the requirements of USP, quantitative procedures [2]. Here, the exceptionally high spectral resolution and sensitivity of the PlasmaQuant PQ 9000 Elite by Analytik Jena allows for an interference-free analysis of trace elements in varying matrices and elemental constellations. Furthermore, the high plasma robustness of the device‘s High-Frequency Generator and the sample introduction system with its centerpiece, the V-Shuttle torch, guarantee a highly accurate and precise analysis of pharmaceutical products. USP Chapter describes two analytical procedures, including sample preparation procedures, instrumental methods, and validation studies and requirements for measuring elemental impurities.

The two compendial procedures are the inductively coupled plasma-based spectrochemical techniques, ICP-OES and ICP-MS. USP chapter defines that all elements of Classes 1 and 2A must be analyzed in oral pharmaceuticals, such as antibiotics (Table 1). Elements of Classes 2B and 3 are only to be analyzed if they are intentionally added to the manufacturing process or to the raw materials.

Analytik Jena’s ICP-OES: PlasmaQuant PQ 9000 presents a simple and effective method for routine preparation and analysis of orally administered antibiotics by ICP-OES in combination with closed vessel microwave digestion. The methodology comprises a microwave digestion to mineralize the pharmaceutical product and a subsequent analysis of all Class 1 and Class 2A target elements by the PlasmaQuant PQ 9000 Elite, a high-resolution ICP-OES. With its High-Frequency Generator and its V-Shuttle torch, the PlasmaQuant PQ 9000 Elite is able to reliably run samples with high matrix content, such as 20 g/L of antibiotics as described in the here presented methodology. The high matrix tolerance allows for lower dilution factors, which benefits the achievable method limits of quantification significantly. Together with the high sensitivity of the system, LOQs in the sub-ppmw range are possible. At the same time, spectral interferences are resolved easily by the high-resolution optical system (2 pm @ 200 nm) ensuring high accuracy of the obtained results as well as high confidence in the developed methodology. Read More here:

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