Skalar automates Total Nitrogen analysis for Pharma application at OctoPlus

OctoPlus is a well-known pharmaceutical development and drug product manufacturing company in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Leiden, the Netherlands. Using its proprietary drug delivery technologies, OctoPlus successfully develops long-acting pharmaceuticals for its clients. One of these products is a long-acting formulation of interferon a-2b, called Locteron®. This product is currently under investigation in a clinical Phase II study for the treatment of chronic hepatitis C.


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Locteron® consists of PolyActive® polymer based microspheres containing interferon. Interferons are natural proteins which are generally produced by the cells of the immune system. To determine the interferon content, the microspheres have to be broken down, where after the interferon is extracted.


For this, the Locteron freeze-dried cakes are incubated in a basic solution, the PolyActive® polymer is dissolved and the interferon is extracted. After that, the samples are further diluted to the working range of the method and injected into the Skalar FormacsTN Total Nitrogen analyzers. As interferon is the only compound in the formulation that contains nitrogen, it is possible to determine the interferon content in the sample based on the analysis of the nitrogen portion. By using the Skalar FormacsTN high temperature combustion analyzer, the lengthy and tedious wet-digestion methods (Kjeldahl) are omitted. Furthermore, the combustion method allows a faster sample throughput and does not suffer from interferences as a result of the PolyActive® polymer.  For calibration, interferon a-2b calibration standards are prepared and injected to create a calibration line. The peak areas of the samples are correlated with the interferon a-2b calibration line to determine the interferon content in each sample.


The FormacsTN Analyzer with its integrated autosampler picks up the sample with a syringe pump and injects it into a high temperature furnace at temperatures up to 900°C containing a catalyst. The samples oxidize to nitric oxide (NO) using catalytic combustion. The carrier gas transports the combustion products via scrubbers to a chemiluminescence detector (CLD) that detects and measures the NO concentration which is proportional to the nitrogen content.





       FormacsTN analyzer at OctoPlus laboratory


Total Nitrogen can be measured in a range from low ppb levels to high ppm levels with high accuracy in a short analysis time.


OctoPlus chose the Skalar FormacsTN Analyzer because the determination of interferon through the measurement of Total Nitrogen is done accurately and rapidly with use of very small sample volumes. Specific points of interest of the Skalar FormacsTN Analyzers are fast response times, its robustness and accessibility.  As the production of Locteron® is controlled by the Total Nitrogen results, a good analytical performance, especially in the low ppb range is very important as the result provides information on the concentration per vial as well as the uniformity of the produced Locteron® drug batches.


These analyses are crucial in order to progress the product successfully through clinical studies.


For more information about OctoPlus, visit