a randomised controlled single-centre open-label pharmacokinetic study to examine various approaches of nicotine delivery using electronic cigarettes.

Introduction:
This text is a scientific report of a randomized controlled open-label pharmacokinetic study that aimed to examine various approaches of nicotine delivery using electronic cigarettes. The study assessed the plasma nicotine pharmacokinetics and product liking of two e-cigarettes with different nicotine e-liquid formulations and a conventional cigarette among 24 dual users of cigarettes and e-cigarettes. The key points of the study are summarized below.

Key Points:

* The study used a randomized, single-center, non-blinded, eight-arm cross-over PK study design registered in the International Standard Randomised Controlled Trial Number (ISRCTN) database.
* The study recruited 24 healthy dual-users of cigarettes and e-cigarettes who were daily e-cigarette users and active smokers of combustible cigarettes and/or roll-your-own cigarettes.
* Two e-cigarette devices were under investigation in this study: Vype ePen, a commercially available closed-system e-cigarette with a silica rope wick, and Vype ePen3, a commercially sourced closed-system e-cigarette with a cotton wick.
* The study assessed the plasma nicotine concentration following the use of e-cigarettes and combustible cigarettes, comparing different products and e-liquids to assess the effect of delivery of greater aerosol mass, protonated versus unprotonated nicotine, and increasing e-liquid nicotine concentration on both nicotine delivery and subjective consumer product liking.
* a fixed puffing regime was used to mimic real-life use as much as possible, and the effect of puffing regime was also assessed.
* The study found that nicotine bioavailability was greater for Vype ePen3 with greater aerosol mass delivery than for Vype ePen. Protonated nicotine (18 mg/mL, medium protonation) e-liquid yielded higher nicotine bioavailability than unprotonated nicotine (18 mg/mL) e-liquid.
* The study also found that nicotine bioavailability did not differ between nicotine benzoate formulation (30 mg/mL nicotine, high protonation) and combustible cigarettes.

Main Message:
The main message of this study is that Vype ePen3 with protonated nicotine delivers nicotine more efficiently than earlier devices using unprotonated e-liquid, which has the potential to increase product liking. This finding suggests that an initial step to potentially improve the user acceptability of an e-cigarette product might be to match the nicotine delivery of a combustible cigarette during use. The study also highlights the importance of optimizing nicotine delivery and product liking in e-cigarettes to increase sustainable smoking abstinence in smoking populations or smokers with a desire and sufficient motivation to quit smoking.

Ebajemito JK, McEwan M, Gale N, Camacho OM, hardie G, Proctor CJ. a randomised controlled single-centre open-label pharmacokinetic study to examine various approaches of nicotine delivery using electronic cigarettes. Scientific reports. 2020;10(1):19980. doi:10.1038/s41598-020-76610-4