A Novel Puff Recording Electronic Nicotine Delivery System Toward Assessment of Naturalistic Puff Topography and Nicotine Consumption During Ad Libitum Use: An Ancillary Study (Preprint)

Abstract

Assessing naturalistic puff topography of e-cigarettes use is important, as it not only reflects the real-world product application and nicotine abuse liability, but also enables the quantitative risk assessment of harmful exposures from e-cigarette aerosols. Typically, the puff topography is assessed by (1) self-reporting survey, (2) frame-by-frame video recording, or (3) added puff recording sensors (i.e., CReSS). However, none of these methods can accurately, conveniently, and noninvasively determine e-cigarette puff topography in a natural use environment.

Here, we aimed to explore and demonstrate the feasibility of a novel puff recording electronic nicotine delivery system (PR-ENDS) device in measuring naturalistic puff topography and estimating nicotine consumption during the ad libitum use of products among smokers and vapers.

A one-way randomized controlled, open-label puff topography and nicotine pharmacokinetic (PK) assessment was carried out in 24 healthy adult smokers and vapers. Participants were assigned with a randomized product use sequence of PR-ENDS during both controlled and ad libitum use sessions. Blood samples were obtained for plasma nicotine analysis at various time points. During the ad libitum use session, puff topography was measured by CReSS (attached to PR-ENDS), as benchmark, as well as by PR-ENDS itself.

No significant differences of puff topography parameters (number of puffs, total puff duration, average puff duration) between PR-ENDS and CReSS were observed at populational level and across different device powers, e-liquid nicotine strengths, and flavors. The evaluation of nicotine consumption estimated by PR-ENDS suggested that this device can be employed as a convenient tool for estimating nicotine use without measuring e-liquid weight loss between puffs. The linear relationship between PR-ENDS derived nicotine consumption and PK parameter AUCad lib, substantiated the potential of using PR-ENDS as a pragmatic, non-invasive, and convenient means for estimating nicotine intake in human body without blood collections.

As a proof-of-concept, here, it was demonstrated viable to use the novel PR-ENDS device in assessing naturalistic puff topography and estimating nicotine consumption and nicotine intake in human body during ad libitum use. We identified several key factors that can influence users' puff topography, including device power, e-liquid nicotine strengths, and flavors. Together, the results presented in this study pave the way for further studies in real-time measurement of naturalistic puff topography and puffing behavior in real world.