"Nonetheless, although the pharmacokinetics of some smokeless tobacco products may overlap with those of medicinal nicotine products, medicinal products tend to have a slower rate and a lower amount of nicotine absorption than do the most popular brands of conventional smokeless tobacco products (Kotlyar et al. 2007). Among the medicinal nicotine products, nicotine nasal spray has the fastest rate of nicotine absorption, followed by nicotine gum, the nicotine lozenge, and the nicotine patch.
"Together, these results demonstrate that the nicotine pharmacokinetics associated with cigarette smoking is likely to lead to high potential for addiction, whereas medicinal nicotine products have relatively minimal potential for addiction. For example, the extent of liking, and therefore the addiction potential for these products, are related to the speed of nicotine delivery (Henningfield and Keenan 1993). Nicotine delivered through cigarette smoking and intravenously shows the greatest dose-related liking for the drug, and nicotine delivered transdermally is associated with the least liking (Henningfield and Keenan 1993; Stratton et al. 2001)."


US Department of Health and Human Services. "How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General." Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2010, p. 114.