Progress in the release and physiological effects of different forms of nicotine.

There are different forms of nicotine in tobacco and tobacco products, and the differences in their contents significantly impact tobacco products. Based on a brief review of nicotine forms, the research on the differences in the release and physiological effects of different forms of nicotine is reviewed. It pointed out that: due to differences in physicochemical properties, freebase nicotine in tobacco products is more easily released into the aerosol; in terms of sensory effects and freebase nicotine is more irritating, and nicotine salts are relatively softer; in terms of absorption rate, due to the existence of multiple modes of administration, the absorption rate of different forms of nicotine exists in terms of toxicity, free nicotine is generally less toxic than nicotine salts, but the toxicity of nicotine salts varies depending on the type of acid ions; in terms of addictiveness, nicotine salts may be more addictive than free nicotine and may vary depending on the type of acid ions. In the future, the differences in ab- sorption rate, toxicity and addictive physiological effects of freebase nicotine and nicotine salts and their potential mechanisms should be thoroughly investigated to better guide the application of nicotine salts in tobacco products. [ABSTRACT FROM AUTHOR]