Biopharmaceutical Impurity Investigation

Impurity Investigations

Chemical impurity analysis is critical in pharmaceutical and medical device development because impurities can impact the safety and efficacy of final therapeutic products. Examples of chemical impurities include: starting raw materials, by-products, intermediates, degradants, reagents, ligands, catalysts, heavy metals, residual metals, or any other materials or process aids in the production process.

Regulations for pharmaceutical organic impurities include USP general chapter <1086> “Impurities in Drug Substances and Drug Products” and USP <476> “Organic Impurities in Drug Substances and Drug Products”. USP <232> and <233> provide guidelines for elemental impurities.

A Degradant ID Case Study:

EKG was approached by a biopharmaceutical client who had recently observed several presumed degradation products during stability assessment of their drug product tablets, at elevated temperature and high humidity. The client wanted identification of 8 compounds at specific relative retention times, and provided their method and example chromatogram.

The first step at EKG Labs was to transfer their method, both the instrumental HPLC method and the complex sample extraction procedure, from their lab to ours. The successful transfer is demonstrated in the chromatograms below.

HPLC DAD chromatogram provided by client, showing 8 targeted peaks for identification
client provided HPLC chromatogram
HPLC DAD chromatogram generated at EKG Labs, showing successful method transfer
EKG generated HPLC chromatogram

Once we knew we could directly target each of the 8 compounds, we began assessing mass spectral data.  Using parent ion masses, empirical formulas were generated for each compound. Then, through MS/MS fragmentation analysis and working in close partnership with the client, final impurity structures and mechanisms were proposed. The MS data indicated degradation was occurring by an oxidative pathway rather than by hydrolytic degradation.

Three peaks correlated to primary degradation products, and three other compounds likely arose from subsequent reaction with these degradation products, one of which was identified as the primary metabolic product of the drug substance. Two impurities were determined to be process-related impurities present in the drug substance.

EKG Labs successfully identified all 8 impurity peaks, and the client was able to change an aspect of their manufacturing and formulating processes to mitigate the possibility of these impurities appearing.

Impurities Testing at EKG Labs

EKG Labs provides impurity testing services to the pharmaceutical and medical device industries. We can perform impurity identification in accordance with FDA and ICH guidelines for impurities. Using our state-of-the-art instrumentation, EKG Labs has the experience to isolate, analyze, and identify impurities. We have experience demonstrating precise recovery even in most challenging matrices and can extract your unique sample as necessary. EKG Labs can also develop and validate a risk-based, product-specific method in order to monitor one or more targeted compounds. At EKG Labs we work with you to provide a customized solution to your impurity identification and analysis needs.

EKG Labs is an analytical service provider for the pharmaceutical and medical device industries. Our wide variety of analytical services support product development, regulatory filings, and analytical chemistry investigations.

If you are experiencing a challenge with impurities or need analytical services to support your product development, please contact us at or at 810-354-5229.