John P. Jasper
Molecular Isotope Technologies, LLC, 8 Old Oak Lane, Niantic CT 06357-1815
Stable isotopes are non-radioactive chemical tracers that are relatively unexploited by the pharmaceutical industry as compared to the natural sciences. Stable isotope ratios are measured by combustion and mass spectrometric analyses of either bulk phases or specific compounds.
• Bulk phases are typically analyzed by:

• Offline combustion followed by dual-inlet mass spectrometry; or
• Online combustion coupled with isotope-ratio-monitoring/mass spectrometry (irmMS).

• Specific compounds are analyzed by:

• Gas chromatography coupled with irmMS (irmGCMS); or,
• Liquid chromatography coupled with irmMS (irmLCMS), depending on the chromatographic properties of the analytes.

Ten major points regarding the properties and uses of stable isotopes in the pharmaceutical industry are discussed and illustrated here, including the suggestion of "Isotope Product Authenticity" of APIs and drug products.

*Now Published as:

Jasper, J. P. (1999). The increasing use of stable isotopes in the pharmaceutical industry. Pharm. Tech. 23(10):106-114.

An informal, follow-up talk at the Sixth Canadian CF-IRMS Workshop by the author led to a publication on the topic of estimating precision (uncertainty) in stable-isotopic measurements:

Jasper, J. P. (2001). Quantitative estimates of precision for molecular isotopic measurements. Rap. Comm. Mass Spec. 15:1554-1557.