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Effect of pH of Smokeless Tobacco Products on the Pharmacokinetics of Nicotine in Current Users

Principal Investigator: Wallace Pickworth and Elena Mishina

Funding Mechanism: Research Contract

ID number: HHSF223201310030I

Award Date: 7/14/2015

Institution: Battelle Memorial Institute


The absorption of nicotine from smokeless tobacco (ST) may be affected by the pH of the product. Increasing the pH of an ST product increases the amount of free base nicotine (the most potent and easily-absorbed form of nicotine) and may increase absorption through the mouth. Although ST products are typically buffered with an alkaline pH (presumably) to facilitate oral absorption of nicotine, clinical data examining this phenomenon are sparse. The goal of this study is to determine whether increasing the pH of an ST product correlates with free base nicotine exposures measured clinically. Study aims are: (1) to evaluate the effect of pH values on the nicotine pharmacokinetics of ST products; and (2) to evaluate the pharmacodynamic effects (e.g., subjective and physiological effects) of ST products with prospectively adjusted pH values. Investigators will ask 40 adult ST users to test one of four ST products (with an adjusted pH of 5, 7.7, 8.2, and 8.6) or a placebo product. Participants will use each product for 30 minutes during a laboratory session. During each session, a series of blood samples will be obtained to determine the time course and nicotine levels resulting from ST product use. In addition, subjective assessments will be administered to determine the qualitative effects of ST product use (e.g., questions about “liking”). Study findings may inform regulatory activities related to smokeless tobacco.