Nicotine Dosimetry in Evaluating Electronic Cigarettes Compared to Cigarette Smoking: Implications for Tobacco Regulatory Science.

The delivery and systemic absorption of nicotine are important for assessing the potential safety and efficacy of novel inhaled nicotine delivery devices. We describe an experimental approach for examining systemic nicotine intake, looking at individual variability, comparing JUUL electronic cigarettes and cigarette smoking, and comparing standardized puffing and ad libitum use. Fourteen cigarette smokers who were infrequent e-cigarette users vaped JUUL or smoked cigarettes, both in a standardized session (ten 3.5 s puffs over 5 min) and in a 4 h ad libitum use session. Plasma nicotine concentrations were measured, and using sex and body weight-based population nicotine clearance predictions, systemic nicotine dose was estimated in each session. The pharmacokinetically (PK)-estimated nicotine dose in the standardized session averaged 0.55 mg (range 0.16-0.82) for JUUL and 1.15 mg (range 0.35-4.56) for cigarette smoking. The PK-estimated dose with ad libitum use averaged 4.1 mg (range 0.4-9.5) for JUUL and 5.0 mg (range 1.5-15) for smoking (average 3.4 cigarettes). Within individual correlations, comparing PK-estimated dose for JUUL use with standardized vs ad libitum session was weak (