Dissolution and physical characterization of oral nicotine pouch products

In this study, we conducted a comprehensive analysis of seven commercially available nicotine pouch products, including on!, Zyn, Velo, Dryft, Rogue, Volt, and Loop nicotine pouches. Analyses include nicotine content, nicotine dissolution release, particle size, imaging (bulk filler and outer pouch material), bulk density (tapped and untapped), true density, crystallinity, solubility, oven volatiles (OV as measured by percent moisture content, % MC), pH of aqueous extracts, water activity, and extract viscosity. The nicotine dissolution profiles showed a faster release for on!, Zyn, and Rogue when compared to Velo, Dryft, Volt, and Loop nicotine pouches. When all nicotine pouches release profiles were compared to on!, only Zyn and Rogue were found equivalent. Particle size analysis revealed Gaussian-like distributions for on!, Rogue, and Zyn nicotine pouches. The remaining products displayed bimodal particle size distributions. Tapped and untapped bulk densities were measured to assess the flowability of the filler in all seven nicotine pouches. Rogue and Loop nicotine pouches exhibited the highest and lowest flowabilities, respectively. Solubility data indicated that Zyn nicotine pouches had the highest percentage of soluble components, whereas Rogue nicotine pouches had the lowest. Rheology results from the nicotine pouch extracts in artificial saliva showed the highest viscosity for Loop and lowest viscosity for Volt and Rogue nicotine pouches. All products were found to have crystalline structures with both high and low temperature melting points. Our results indicate that nicotine pouch products exhibit differences and similarities in their physicochemical properties, providing valuable insights into understanding their formulation and development.