A novel model mouth system for evaluation of In Vitro release of nicotine from moist snuff

Mass spectrometry-based metabolomics study of nicotine exposure in THP-1 monocytes

The tobacco alkaloid nicotine is known for its activation of neuronal nicotinic acetylcholine receptors. Nicotine is consumed in different ways such as through conventional smoking, e-cigarettes, snuff or nicotine pouches. The use of snuff has been associated with several adverse health effects, such as inflammatory reactions of the oral mucosa and oral cavity cancer. We performed a metabolomic analysis of nicotine-exposed THP-1 human monocytes. Cells were exposed to 5 mM of the alkaloid for up to 4 h, and cell extracts and medium subjected to untargeted liquid chromatography high-resolution mass spectrometry. Raw data processing revealed 17 nicotine biotransformation products. Among these, cotinine and nornicotine were identified as the two major cellular biotransformation products. The application of multi- and univariate statistical analyses resulted in the annotation, up to a certain level of identification, of 12 compounds in the cell extracts and 13 compounds in the medium that were altered by nicotine exposure. Of these, four were verified as methylthioadenosine, cytosine, uric acid, and L-glutamate. Methylthioadenosine levels were affected in both cells and the medium, while cytosine, uric acid, and L-glutamate levels were affected in the medium only. The effects of smoking on the pathways involving these metabolites have been previously demonstrated in humans. Most of the other discriminating compounds, which were merely tentatively or not fully identified, were amino acids or amino acid derivatives. In conclusion, our preliminary data suggest that some of the potentially adverse effects related to smoking may also be expected when nicotine is consumed via snuff or nicotine pouches.

Flavor Classification/Categorization and Differential Toxicity of Oral Nicotine Pouches (ONPs) in Oral Gingival Epithelial Cells and Bronchial Epithelial Cells

Oral nicotine pouches (ONPs) are a modern form of smokeless tobacco products sold by several brands in the U.S., which comprise a significant portion of non-combustible nicotine-containing product (NCNP) sales to date. ONPs are available in various flavors and may contain either tobacco-derived nicotine (TDN) or tobacco-free nicotine (TFN). The growth in popularity of these products has raised concerns that flavored ONPs may cause adverse oral health effects and promote systemic toxic effects due to nicotine and other ONP by-products being absorbed into the circulatory system through oral mucosa. We hypothesized that flavored ONPs are unsafe and likely to cause oral and pulmonary inflammation in oral and respiratory epithelial cells. Before analyzing the effects of ONPs, we first classified ONPs sold in the U.S. based on their flavor and the flavor category to which they belonged using a wheel diagram. Human gingival epithelial cells (HGEP) were treated with flavored ONP extracts of tobacco (original, smooth), menthol (wintergreen and cool cider), and fruit flavor (americana and citrus), each from the TDN and TFN groups. The levels of ONP-induced inflammatory cytokine release (TNF-α, IL-6, and IL-8) by ELISA, cellular reactive oxygen species (ROS) production by CellRox Green, and cytotoxicity by lactate dehydrogenase (LDH) release assay in HGEP cells were assessed. Flavored ONP extracts elicited differential toxicities in a dose- and extract-dependent manner in HGEP cells 24 h post-treatment. Both fruit TDN and TFN extracts resulted in the greatest cytotoxicity. Tobacco- and fruit-flavored, but not menthol-flavored, ONPs resulted in increased ROS production 4 h post-treatment. Flavored ONPs led to differential cytokine release (TNF-α, IL-6, and IL-8) which varied by flavor (menthol, tobacco, or fruit) and nicotine (TDN vs. TFN) 24 h post-treatment. Menthol-flavored ONPs led to the most significant TNF-α release; fruit TFN resulted in the most significant IL-6 release; and fruit TDN and tobacco TFN led to the highest release of IL-8. Subsequently, human bronchial epithelial cells (16-HBE and BEAS-2B) were also treated with flavored ONP extracts, and similar assays were evaluated. Here, the lowest concentration treatments displayed increased cytotoxicity. The most striking response was observed among cells treated with spearmint and tobacco flavored ONPs. Our data suggest that flavored ONPs are unsafe and likely to cause systemic and local toxicological responses during chronic usage.

An in Vitro Study of Constituents Released from Smokeless Tobacco Products into Human Saliva

Smokeless tobacco (ST) products are used worldwide, and consumption is increasing in the USA. Although ST products are considered to occupy a different position on the tobacco product continuum of risk compared to combusted tobacco products, they can still lead to health problems, including cancer, dental problems and changes in heart rate and blood pressure. Therefore, the determination of harmful and potentially harmful constituents released from ST products into human saliva is important. Four certified reference ST products were tested in this study: loose leaf chewing tobacco (3S1), Swedish-style snus (1S4), snus (1S5) and moist snuff (3S3). These certified reference ST products are manufactured for research purposes, not for human consumption. The reference ST products were used in this study because they have been well characterized and are intended and designed to represent commercial ST products. The reference ST products were incubated in human saliva at 37°C with a range of incubation times for the evaluation of constituents released from these products into human saliva. In this study, alkaloids (nicotine and cotinine), tobacco-specific N-nitrosamines (TSNAs) (N'-nitrosornicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone) and benzo[α]pyrene (B[α]P) in the reference ST products and saliva samples were determined by gas chromatography--mass spectrometry (GC--MS), gas chromatography--flame ionization detection (GC--FID), or ultra-performance liquid chromatography--tandem mass spectrometry (UPLC--MS-MS). Our results indicate that the amounts of each constituent released from the reference ST products were altered by the tobacco cut size and product format (pouched or unpouched). The constituents (TSNAs and alkaloids) in moist snuff and loose leaf chewing tobacco were released faster compared to those in Swedish-style snus and snus. B[α]P was only detected in reference moist snuff samples, and only 3.4% of the total B[α]P was released into human saliva after incubation for 60 min, whereas higher percentages of total TSNAs and alkaloids were released at different rates from the four reference ST products.

Introducing a Novel Biorelevant In Vitro Dissolution Method for the Assessment of Nicotine Release from Oral Tobacco-Derived Nicotine (OTDN) and Snus Products

The rate at which oral tobacco-derived nicotine (OTDN) and snus pouches release nicotine into saliva is crucial to determine product performance. As no standardized method is available for this purpose, this study sought to develop a biorelevant dissolution method that could both discriminate between different products and predict in vivo behavior. Using a μDISS Profiler™ as a surrogate for the US Pharmacopoeia standard apparatuses and a custom-made sinker, nicotine release from an OTDN pouch product (ZYN® Dry Smooth) and a snus product (General® Pouched Snus White Portion Large) was determined in biorelevant volumes (10 mL) of artificial saliva. In addition, nicotine extraction in vivo was measured for both products. Strikingly, the method showed distinct dissolution curves for OTDN and snus pouches, and the nicotine release observed in vitro did not significantly differ from the nicotine extracted in vivo. The custom-made sinker was designed to accommodate both loose and pouched oral tobacco/nicotine products, and thus the proposed in vitro dissolution method is suitable to assess nicotine release from OTDN and snus pouches. Apart from providing individual dissolution curves, the method was also able to predict in vivo nicotine extraction. Thus, this method could serve as a (biorelevant) monograph for product equivalence studies.

Development and Validation Of A Discriminatory Dissolution Method for Portioned Moist Snuff and Snus

Portioned moist snuff and snus, two subcategories of smokeless tobacco products (STP) were dissolution tested as a quality control test. A USP Apparatus 4 was employed to develop and validate the method. The method was assessed based on time to reach nicotine dissolution plateau, percentage difference between two profiles at each time point, relative standard deviation (RSD), and f1 (similarity) and f2 (dissimilarity) values. Based on these criteria, 200 ml volume and 8 ml/min flow were found be discriminatory. The amount of nicotine dissolved from the nine products varied widely (2.0-3.4, 2.1-4.1, 3.3-4.6, 5.5-6.6, 6.9-9.1, 11.5-14.2, 12.5-14.6, 14.0-15.5, and 15.5-19.6 mg/pouch at 60 min). RSDs of the dissolution ranges were more than 20% at earlier time points and less than 20% at later timepoints. The developed method produced distinct profiles for all the tested products, which was further confirmed by f1>15 and f2<50 values. In conclusion, the developed method was discriminatory and can be employed as a quality control test and to differentiate among moist snuff and snus products.

Dissolution Testing of Nicotine Release from OTDN Pouches: Product Characterization and Product-to-Product Comparison

In recent years, oral tobacco-derived nicotine (OTDN) pouches have emerged as a new oral tobacco product category. They are available in a variety of flavors and do not contain cut or ground tobacco leaf. The on!® nicotine pouches fall within this category of OTDN products and are currently marketed in seven (7) flavors with five (5) different nicotine levels. Evaluation of the nicotine release from these products is valuable for product assessment and product-to-product comparisons. In this work, we characterized the in vitro release profiles of nicotine from the 35 varieties of on!® nicotine pouches using a fit-for-purpose dissolution method, employing the U.S. Pharmacopeia flow-through cell dissolution apparatus 4 (USP-4). The nicotine release profiles were compared using the FDA’s Guidance for Industry: Dissolution Testing of Immediate Release Solid Oral Dosage Forms. The cumulative release profiles of nicotine show a dose dependent response for all nicotine levels. The on!® nicotine pouches exhibit equivalent percent nicotine release rates for each flavor variant across all nicotine levels. Furthermore, the nicotine release profiles from on!® nicotine pouches were compared to a variety of other commercially available OTDN pouches and traditional pouched smokeless tobacco products. The percent nicotine release rates were found to be dependent on the product characteristics, showing similarities and differences in the nicotine release profiles between the on!® nicotine pouches and other compared products.

Formulation and Characterization of Gelatin-Based Hydrogels for the Encapsulation of Kluyveromyces lactis-Applications in Packed-Bed Reactors and Probiotics Delivery in Humans

One of the main issues when orally administering microorganism-based probiotics is the significant loss of bioactivity as they pass through the gastrointestinal (GI) tract. To overcome these issues, here, we propose to encapsulate the probiotic yeast Kluyveromyces lactis on chemically crosslinked gelatin hydrogels as a means to protect the bioactive agents in different environments. Hydrogels were prepared by the chemical crosslinking of gelatin, which is commercially available and inexpensive. This is crucial to ensure scalability and cost-effectiveness. To explore changes in key physicochemical parameters and their impact on cell viability, we varied the concentration of the crosslinking agent (glutaraldehyde) and the gelatin. The synthesized hydrogels were characterized in terms of morphological, physical-chemical, mechanical, thermal and rheological properties. This comprehensive characterization allowed us to identify critical parameters to facilitate encapsulation and enhance cell survival. Mainly due to pore size in the range of 5-10 μm, sufficient rigidity (breaking forces of about 1 N), low brittleness and structural stability under swelling and relatively high shear conditions, we selected hydrogels with a high concentration of gelatin (7.5% (w/v)) and concentrations of the crosslinking agent of 3.0% and 5.0% (w/w) for cell encapsulation. Yeasts were encapsulated with an efficiency of about 10% and subsequently tested in bioreactor operation and GI tract simulated media, thereby leading to cell viability levels that approached 95% and 50%, respectively. After testing, the hydrogels' firmness was only reduced to half of the initial value and maintained resistance to shear even under extreme pH conditions. The mechanisms underlying the observed mechanical response will require further investigation. These encouraging results, added to the superior structural stability after the treatments, indicate that the proposed encapsulates are suitable to overcome most of the major issues of oral administration of probiotics and open the possibility to explore additional biotech applications further.

Is Sodium Carbonate in Snuff a Causative Factor for Oral Mucosal Lesions: A Cross-sectional Analysis

Aims and Objectives:

Nicotine absorption through the mucous membrane is directly proportional to pH, so the snuff is buffered to pH of 8–9 by adding sodium carbonate. The objective of the present study is to assess the impact of various forms of sodium carbonate in snuff on mucosal conditions.

Materials and Methods:

The present cross-sectional study was conducted on 284 participants. Snuff users adding sodium carbonate were further splitted into two groups, that is, one group using sodium carbonate in premixed form, that is, (already mixed within pouches) and other group adding sodium carbonate separately (freshly mixed). The parametric one-way (ANOVA) of variance, stepwise regression analysis, and multiple logistic regression analysis have been done to narrate the relationship between variables of different forms of sodium carbonate in snuff and different oral conditions.

Results:

The statistics of our study reveals highly significant relationship between snuff users using sodium carbonate in freshly mixed (0.001**) form than that of premixed form (P = 0.030*).

Conclusion:

The present study narrates that there seems to be liaison between the use of sodium carbonate in snuff and oral mucosal lesions.