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Using the Chemistry and Reactivity of Halogenated Rubber Oligomers in Identifying Unknowns in Extractables Studies

Published Date: October 27, 2023

Join this on-demand webinar to learn more about the possible role of halogenated rubber oligomers in identifying unknowns in extractables studies.

Key Takeaways

  • Challenges in using LC/MS data to identify unknown compounds
  • How to combine different information to identify unknown extractables – „Puzzle approach“
  • Example: Rubber crosslinkers and halogenated rubber oligomers
  • Expanding the concept – A systematic research program using reactive rubber oligomers

More Information

It is widely acknowledged that halogenated rubber oligomers constitute a group of compounds frequently encountered both as extractables in controlled extraction studies and, in specific cases, as leachables in pharmaceutical products.

Although there is an ongoing debate upon the toxicity of these compounds, it is indisputable that they act as potent alkylating agents with high reactivity towards certain functional groups. These interactions have been widely observed, resulting in the formation of adducts with various components of the drug products, including active pharmaceutical ingredients (APIs), peptides, proteins, and excipients.

A second observation is that, when performing a controlled extraction study on rubbers using more aggressive solvents such as IPA, Hexane, a potentially more extensive list of “Unknowns” emerges in both GC/MS and LC/MS. The origin of these unknown compounds is not always very clear.

The question that arises from this observation, considering the high reactivity of halogenated rubber oligomers, is whether some of the reported unknowns could potentially be linked to reaction products of rubber oligomers with other rubber ingredients, such as curing agents, activators, accelerators…

Nelson Labs conducted an R&D programme aimed at systematically allowing the reaction of halo rubber oligomers, compounds that are available as analytical standards at Nelson Labs NV, with other rubber ingredients under the typical conditions of rubber curing. The Initial results from this R&D programme will be shared with the audience.

Lothar Habel PhD

Technical Advisor

Dr. Lothar Habel joined Nelson Labs Europe in December 2006 as a Study Director for Extractables and Leachables projects. From the beginning, he directed his efforts toward parenteral and injectable applications, including rubber compounds, a field in which he honed his expertise over several years. In 2023, he transitioned internally to the position of Technical Advisor. Dr. Habel began his academic and professional career with the small-scale synthesis of organic chemical compounds, subsequently dedicating several years to research projects at universities and private enterprises in both Germany and Belgium.

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