Background and aims

Vaporized nicotine products (VNPs) can vary in important characteristics including size, shape, flavor and nicotine yield. We examined whether complex interactions among these characteristics could affect smokers' VNP perceptions and usage patterns.

Design

A within-subject randomized cross-over trial.

Setting

Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.

Participants

Eighteen daily cigarette smokers.

Measurements

Participants attended eight weekly visits during which they sampled six different VNPs (disposable, rechargeable, eGO, mod, e-Cigar and e-Pipe) with tobacco-flavored e-liquid. Prior to device use, participants completed product-ranking questionnaires. Participants completed controlled puffing sessions during each of the six trials, after which satisfaction questionnaires were completed and blood samples were taken.

Findings

Initial perceptions showed that the smallest device (disposable) was ranked as safer compared with a larger device (e-Pipe) (P < 0.05). Participants rated the eGO and mod devices higher on satisfaction and enjoyment from use, taste, pleasantness, harshness ('throat hit') and speed of effect, but lower on perceived health risk and embarrassment from use (P < 0.05). All devices had a lower C_max than the combustible cigarette (P < 0.05), but there were differences among devices (P < 0.05). The mod, e-Pipe and eGO provided the highest amount of perceived smoking urge relief, and this correlated strongly with C_max across all devices (R²  = 0.8614, P = 0.007). The perceived speed of urge relief was not correlated with T_max (R²  = 0.0035, P = 0.911) CONCLUSIONS: Daily cigarette smokers testing six types of vaporized nicotine products (VNPs) reported that they varied in taste, amount of withdrawal relief, harshness, embarrassment from use, perceived health risk and subjective and objective nicotine delivery. The eGO and mod models have properties that may make them most effective for cigarette substitution among smokers who intend to switch to a VNP.

Rationale

There is limited understanding regarding how various e-cigarette flavorings may influence the behavior of non-regular e-cigarette users who are regular cigarette smokers.

Objectives

To assess differences in nicotine delivery, puffing topography, subjective effects, and user satisfaction from different flavored e-liquids.

Methods

Eighteen daily smokers (average age, 44.1 ± 7.0; 9 males; average CPD, 13.0 ± 5.8) smoked their tobacco cigarettes during an initial visit and returned five times to try an e-cigarette (eGo type) refilled with a nicotine solution (24 mg/ml) of five different flavors: cherry, tobacco, espresso, menthol, and vanilla (randomized order). Assessments at each visit included puffing topography, blood samples for nicotine analysis, and subjective reports of nicotine effects and flavor satisfaction.

Results

Vaping different flavors resulted in different levels of plasma nicotine. The flavor producing the highest plasma nicotine concentration (C_max) was cherry (median 21.2 ng/ml), which was not significantly different than nicotine delivery from a combustible cigarette (29.2 ng/ml, p > .05). Vanilla e-liquid produced the lowest C_max (9.7 ng/ml), and participants tended to puff less frequently on vanilla compared to tobacco flavor (p = .013). Flavors did not differ significantly in the speed of nicotine delivery (T_max). During controlled use, puff duration for all flavors was significantly longer than a combustible cigarette (p < 0.05). After controlling for nicotine delivery, significant differences in flavor enjoyment were detected. Menthol flavored e-liquid was rated as more enjoyable than vanilla and tobacco flavored e-liquids (p < 0.05).

Conclusions

Flavors tested in this study yielded different patterns of nicotine delivery and led to differences in reduction in smoking urges.

Trial registration

ClinicalTrials.gov Identifier: #NCT02575885.

Background and aims

Vaporized nicotine products (VNPs) can vary in important characteristics including size, shape, flavor and nicotine yield. We examined whether complex interactions among these characteristics could affect smokers' VNP perceptions and usage patterns.

Design

A within-subject randomized cross-over trial.

Setting

Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.

Participants

Eighteen daily cigarette smokers.

Measurements

Participants attended eight weekly visits during which they sampled six different VNPs (disposable, rechargeable, eGO, mod, e-Cigar and e-Pipe) with tobacco-flavored e-liquid. Prior to device use, participants completed product-ranking questionnaires. Participants completed controlled puffing sessions during each of the six trials, after which satisfaction questionnaires were completed and blood samples were taken.

Findings

Initial perceptions showed that the smallest device (disposable) was ranked as safer compared with a larger device (e-Pipe) (P < 0.05). Participants rated the eGO and mod devices higher on satisfaction and enjoyment from use, taste, pleasantness, harshness ('throat hit') and speed of effect, but lower on perceived health risk and embarrassment from use (P < 0.05). All devices had a lower C_max than the combustible cigarette (P < 0.05), but there were differences among devices (P < 0.05). The mod, e-Pipe and eGO provided the highest amount of perceived smoking urge relief, and this correlated strongly with C_max across all devices (R²  = 0.8614, P = 0.007). The perceived speed of urge relief was not correlated with T_max (R²  = 0.0035, P = 0.911) CONCLUSIONS: Daily cigarette smokers testing six types of vaporized nicotine products (VNPs) reported that they varied in taste, amount of withdrawal relief, harshness, embarrassment from use, perceived health risk and subjective and objective nicotine delivery. The eGO and mod models have properties that may make them most effective for cigarette substitution among smokers who intend to switch to a VNP.