Analysis of PEG and PPG: ICH Topic Q6B (1) provides a uniform set of internationally accepted principles for characterisation of biotechnological products to support new marketing applications. The document suggests that analyses should be performed to provide information for purity, impurities and contaminants. In addition to characterising the drug product, there exists a requirement to assess the levels of other components present in the formulation, whether they are product or process related.

PEG (Polyethylene glycol), PPG (polypropylene glycol) and various detergents, including TWEEN, are often included in biotechnological products to aid stability and improve solubility. Qualitative and, particularly, quantitative analysis of these components can prove problematical due to the charging profiles exhibited when applied to ES-MS. By taking the appropriate measures during sample/standard preparation and by maintaining close control of instrumental parameters throughout the analyses, it is possible to detect and quantify these essential components accurately and reproducibly.

In addition to the analysis of free PEG, SGS M-Scan also has considerable experience in characterisation of PEGylated proteins, including PEGylation site determination.