Crystal structure of nicotine gentisate and its permeability in pig buccal mucosa
Nicotine compound salt has been widely concerned recently with the continuous expansion of the e-cigarette market. Synthetic nicotine organic acid salt or nicotine complex, instead of monomeric nicotine, is used in the formulation of the next generation tobacco products. Bound nicotine has shown its clear impact on not only the taste but also on the dissolution and absorption of nicotine.
In order to develop a totally different nicotine introduction form for next generation tobacco products, the compound salt of nicotine with gentisic acid was synthesized in this study. The liquid products were crystal cultured in the dark at room temperature. The transparent brown needle crystals were obtained after several weeks. The structure of nicotine gentisate crystal was characterized with the single crystal X-ray diffraction technique. The results indicated that the relative molecular weight was 316.35. The crystal density was 1.342 mg/m3. The crystal belonged to the monoclinic crystal system and the spatial group was P21. Transdermal diffusion experiments of nicotine and nicotine gentisate, in which pig buccal mucosa was used as a cross-membrane carrier, were carried out at different pH levels in vitro. The results suggested that compared to nicotine, nicotine gentisate had a significant effect on the sustained release of nicotine. In addition, the slowing effect was more significant in low pH medium. This study provides a reference for the research and development of a new form of nicotine and its potential application value to the next generation tobacco products.