The effect of electronic cigarette (ECIG) liquid vehicles on ECIG acute effects

 描述（由申请人提供）：电子烟（ECIG）是当今公共卫生中最重要的问题之一，因为它们的流行程度急剧增加。然而，人们对ECIG知之甚少，包括哪些因素可能使它们更容易被使用和滥用。检查影响ECIG尼古丁产量、递送和主观效应的因素对于了解其滥用倾向至关重要。有限的临床前研究表明，尼古丁产量可能会受到两种液体载体（丙二醇（PG）和植物甘油（VG））的比例影响，这两种液体载体最常见于ECIG溶液中。具体而言，较高比例的PG导致较高的尼古丁产量。然而，这项研究中产生的气溶胶并不是由实际ECIG使用者的吸烟行为产生的，这表明发现的尼古丁产量可能并不能指示实际ECIG使用者的尼古丁暴露。此外，PG：VG比例对尼古丁释放的影响以及与ECIG使用相关的主观效应之前尚未进行过研究。本提案介绍了一项由两部分组成的研究。第一个检查PG和VG对尼古丁释放的影响和主观影响，使用受试者内设计。30名经验丰富的ECIG用户将在5种条件下使用ECIG，这5种条件的差异仅在于PG：VG比：100：0、70：30、50：50、30：70和0：100（器械电压、加热器电阻、液体尼古丁浓度、抽吸次数和抽吸间隔均保持不变）。将记录每种条件下的血浆尼古丁浓度、主观效应和抽吸行为。第二个将使用ECIG用户在研究的第一部分和相同的实验条件下记录的抽吸行为产生ECIG气溶胶（例如，PG：VG比率）。将捕获产生的气溶胶并评估尼古丁产量。主要假设是，较高比例的PG将导致更大的尼古丁释放和主观效应特征，表明ECIG使用者的滥用倾向较高，并产生尼古丁产量较高的气雾剂。该项目的结果将进一步了解影响ECIG滥用责任的因素，并为这些产品的监管提供信息。

 DESCRIPTION (provided by applicant): Electronic cigarettes (ECIGs) are among the most important issues in public health today due to their dramatic increase in popularity. However, very little is known about ECIGs, including what factors may make them more likely to be used and abused. Examining factors that influence nicotine yield, delivery, and subjective effects from ECIGs is essential to understanding their abuse liability. Limited pre-clinical research has revealed that nicotine yield may be influenced by the ratio of the two liquid vehicles, propylene glycol (PG) and vegetable glycerin (VG), most commonly found in ECIG solutions. Specifically, higher proportions of PG result in greater nicotine yields. However, the aerosols generated in this research were not produced by actual ECIG users' puffing behaviors, suggesting that the nicotine yields found may not be indicative of actual ECIG users' nicotine exposure. Moreover, the influence of PG:VG ratio on nicotine delivery and subjective effects associated with ECIG use has not been examined previously. This proposal describes a two-part study. The first examines the effect of PG and VG on nicotine delivery and subjective effects using a within-subjects design. Thirty experienced ECIG users will use an ECIG in five conditions that will differ only by the PG:VG ratio: 100:0, 70:30, 50:50, 30:70, and 0:100 (device voltage, heater resistance, liquid nicotine concentration, puff number, and interpuff interval all will be held constant). Plasma nicotine concentration, subjective effects, and puffing behaviors will be recorded in each condition. The second will generate ECIG aerosols using the puffing behavior recorded from ECIG users in the first part of the study and under identical experimental conditions (e.g., PG:VG ratio). The aerosol produced will be captured and assessed for nicotine yield. The primary hypotheses are that higher proportions of PG will result in greater nicotine delivery and subjective effect profiles suggestive of higher abuse liability in ECIG users and produce aerosols with higher nicotine yields. Results from this project will result in further understanding of the factors that influence the abuse liability of ECIGs and could inform regulation of these products.