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

 描述(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，因为它们的普及率急剧上升。然而，人们对ECIG知之甚少，包括哪些因素可能使它们更有可能被使用和滥用。检查影响尼古丁产量、释放和ECIG的主观影响的因素对于了解其滥用倾向是至关重要的。有限的临床前研究表明，尼古丁的产量可能会受到两种液体载体丙二醇(PG)和植物甘油(VG)的比例的影响，这两种液体最常见于ECIG溶液中。具体地说，PG比例越高，尼古丁产量就越大。然而，这项研究中产生的气雾剂并不是由ECIG使用者的实际吸烟行为产生的，这表明所发现的尼古丁产量可能不能指示ECIG使用者实际接触尼古丁。此外，PG/VG比例对尼古丁释放的影响以及与使用ECIG相关的主观影响以前还没有被研究过。这份提案描述了一项由两部分组成的研究。第一项研究采用受试者内设计，考察PG和VG对尼古丁释放的影响和主观影响。30名经验丰富的ECIG用户将在五种情况下使用ECIG，这五种条件仅在PG：VG比率上有所不同：100：0、70：30、50：50、30：70和0：100(装置电压、加热器电阻、液体尼古丁浓度、吸烟数和间歇时间间隔都将保持不变)。在每种情况下，将记录血浆尼古丁浓度、主观影响和吸烟行为。第二种方法将在相同的实验条件(例如PG：VG比率)下，使用在研究第一部分中记录的ECIG使用者的吹气行为来产生ECIG气雾剂。产生的气雾剂将被捕获并评估尼古丁的产量。主要的假设是，较高比例的PG将导致更多的尼古丁释放，以及暗示ECIG使用者更容易滥用的主观影响概况，并产生具有更高尼古丁产量的气雾剂。该项目的结果将有助于进一步了解影响ECIGs滥用责任的因素，并可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.