Real-Time Monitoring of Nicotine Release Behavior from Smokeless Tobacco (Snus) Based on Fiber Optic Sensing Technology

Introduction: To strengthen the safety control of smokeless tobacco (snus) products, an accurate method to test the nicotine release behavior from snus is very necessary. Methods: A laboratory-made flow-through device was designed to simulate snus using condition in the mouth, which was integrated with a commercial drug dissolution analyzer. Nicotine was gradually released from snus and dropped into the release solution. The release solution was analyzed by ultraviolet spectroscopy, and the spectral signal input to the system was detected by fiber optic probe and automatically processed by computer. The nicotine release behavior diagram was thus obtained. Also, the nicotine dissolution rate coefficient ([alpha]) could be calculated. Results: The results show that there was a great linear relationship between the absorbance and concentration of a nicotine standard solution at 260 nm in the range of 10-80 [micro]g/mL. The relative standard deviation (RSD) of nicotine release at several time periods was between 10.35% and 12.74%, indicating good repeatability. Approximately 17-85% of nicotine was released from 16 commercial snus products. The [alpha] values were between 0.008 and 0.071. Conclusions: This nicotine dissolution analyzer was designed by integrating fiber optic sensing technology, chemical spectroscopic analytical technology, and computer data processing technology. The sampling time and measurement time intervals of this method had a precision of several seconds. Thus, the design objective of the fiber optic sensing nicotine dissolution analyzer was achieved; that is, in vitro, continuous, real-time, online analysis of nicotine dissolution behavior of snus. KEYWORDS: Snus, nicotine dissolution behavior, fiber optic sensing technology, dissolution