Biomarkers of Exposure Specific to E-vapor Products Based on Stable-Isotope Labeled Ingredients.

Introduction:
This text provides an in-depth analysis of a clinical study that investigates the applicability of stable-isotope e-liquid ingredients for exposure studies in vapers. The study includes 25 healthy male subjects who were either smokers or experienced vapers. The vapers were divided into two groups and were given e-liquids spiked with 13C-labeled PG, G, and D7-nicotine at high and low wattage conditions. The smokers were given non-filter cigarettes spiked with 13C-labeled PG, G, and D7-nicotine as a positive control. Biomarkers such as PG, G, nicotine, and its major metabolites were measured in plasma, urine, and saliva.

Key Points:

* The study was conducted in two parts, Part A and Part B, with Part A being an in-clinic study and Part B being an ambulatory study.
* The study included 25 healthy male subjects, 5 of whom were smokers, and 20 who were experienced vapers.
* The vapers were divided into two groups and were given e-liquids spiked with 13C-labeled PG, G, and D7-nicotine at high and low wattage conditions.
* The smokers were given non-filter cigarettes spiked with 13C-labeled PG, G, and D7-nicotine as a positive control.
* Biomarkers such as PG, G, nicotine, and its major metabolites were measured in plasma, urine, and saliva.
* The study found that the application of labeled e-liquid ingredients allows the accurate quantification of the dose of nicotine and PG when other nicotine and tobacco products were used simultaneously.
* The study also found that unchanged G was not assessable by this approach.

Main Message:
The study demonstrates the feasibility of using stable-isotope labeled e-liquid ingredients for exposure studies in vapers. The results of this study provide a foundation for future studies that aim to investigate the absorption of potential PG-, G-, and nicotine-derived vapor constituents by vaping. This approach will help in understanding the risks associated with e-cigarette use and will inform regulatory decisions regarding their use. As an expert in regulatory matters, understanding the design and findings of this study is crucial for making informed decisions regarding e-cigarette regulation.

Landmesser a, Scherer M, Pluym N, et al. Biomarkers of Exposure Specific to E-vapor Products Based on Stable-Isotope Labeled Ingredients. Nicotine Tob Res. 2019;21:314-322. doi:10.1093/ntr/nty204