Nicotine Absorption from Smokeless Tobacco Modified to Adjust pH

Evaluating the Role of Nicotine Stereoisomer on Nicotine Pouch Abuse Liability: A Randomized Crossover Trial

INTRODUCTION

Many oral nicotine pouch (ONP) brands use synthetic nicotine, which typically contains a racemic (50:50) mixture of nicotine's two stereoisomers: S-nicotine and R-nicotine. Because tobacco-derived nicotine contains more than 99% S-nicotine, the effects of R-nicotine in humans are not well known. We compared systemic nicotine exposure and product appeal of ONPs containing more than 99% S-nicotine versus racemic nicotine.

AIMS AND METHODS

N = 18 adult smokers (Mage = 45 years, 66.7% male, 77.8% White) enrolled in a three-visit single-blind, randomized crossover study. During each visit, participants used one wintergreen-flavored, 3 mg nicotine ONP for 30 min following at least12 h nicotine abstinence. Study ONP #1 contained more than 99% S-nicotine and the other two study ONPs contained racemic nicotine (collapsed for analyses). Plasma nicotine assessments and measures of withdrawal relief occurred at t = 0, 5, 15, 30, 60, and 90 min; measures of product appeal were assessed following ONP use.

RESULTS

Using the ONP with more than 99% S-nicotine resulted in greater plasma nicotine concentration from 15 to 90 min (p < .0001) and greater maximum plasma nicotine concentration than the ONPs with racemic nicotine (M = 9.9 ng/mL [SD = 2.5] vs. M = 5.7 ng/mL [SD = 2.8], respectively; p < .0001). Product liking and withdrawal relief were similar across ONPs, although participants reported more "bad effects" when using the ONP with more than 99% S-nicotine.

CONCLUSIONS

Participants reported few subjective differences in ONPs according to nicotine stereoisomer, but plasma nicotine concentration was greater for ONPs using more than 99% S-nicotine. ONPs with more than 99% S-nicotine (vs. racemic nicotine) might be better substitutes for cigarettes, but research into other ONP characteristics (eg flavors, freebase nicotine) is needed to inform regulation.

IMPLICATIONS

Little is known about the effects of racemic (vs. S-) nicotine in humans. In a sample of adults who smoke cigarettes, we identified that oral nicotine pouches containing racemic nicotine exposed participants to less nicotine than oral nicotine pouches containing only S-nicotine, but both types of oral nicotine pouches held similar, moderate appeal. Additional research evaluating the roles that flavorings, total nicotine concentration, and freebase nicotine play in the abuse liability of oral nicotine pouches would inform comprehensive product regulations to support public health.

Evaluating the effects of nicotine concentration on the appeal and nicotine delivery of oral nicotine pouches among rural and Appalachian adults who smoke cigarettes: A randomized cross-over study

BACKGROUND AND AIMS

Oral nicotine pouches (ONPs) probably offer reduced harm compared with cigarettes, but independent data concerning their misuse liability are lacking. We compared nicotine delivery and craving relief from ONPs with different nicotine concentrations to cigarettes.

DESIGN

This was a single-blind, three-visit (≥ 48-hour washout), randomized-cross-over study. Participants were encouraged to complete all study visits in less than 1 month.

SETTING

The study took place in Rural/Appalachian Ohio.

PARTICIPANTS

Participants comprised 30 adults who smoke cigarettes. Participants (meanage  = 34.5) were 60% men and 90% White.

INTERVENTION

Participants who were ≥ 12-hour tobacco-abstinent used: (1) a 3-mg nicotine concentration ONP, (2) a 6-mg nicotine concentration ONP and (3) usual brand cigarette in separate visits. ONPs (wintergreen Zyn) were used for 30 minutes; cigarettes were puffed every 30 sec for 5 minutes.

MEASUREMENTS

Plasma nicotine and self-reported craving were assessed at t = 0, 5, 15, 30, 60 and 90 minutes. The primary outcome was plasma nicotine concentration at t = 30 minutes. A secondary outcome was craving relief at t = 5 minutes.

FINDINGS

At t = 30, mean [95% confidence interval (CI)] plasma nicotine was 9.5 ng/ml (95% CI = 7.1, 11.9 ng/ml) for the 3 mg nicotine ONP, 17.5 ng/ml (95% CI = 13.7, 21.3) for the 6 mg nicotine ONP and 11.4 ng/ml (95% CI = 9.2, 13.6 ng/ml) for the cigarette. Mean plasma nicotine at t = 30 minutes differed between the 3- and 6-mg nicotine ONPs (P = 0.001) and between the 6-mg nicotine ONP and cigarette (P = 0.002). Mean (95% CI) craving at t = 5 minutes was lower for the cigarette (mean = 1.00, 95% CI = 0.61, 1.39) than either the 3 mg (mean = 2.25, 95% CI = 1.68, 2.82; P < 0.0001) or 6 mg nicotine (mean = 2.19, 95% CI = 1.60, 2.79; P < 0.0001) ONP.

CONCLUSIONS

Among adult smokers, using 6-mg nicotine concentration oral nicotine pouches (ONPs) was associated with greater plasma nicotine delivery at 30 minutes than 3-mg ONPs or cigarettes, but neither ONP relieved craving symptoms at 5 minutes as strongly as a cigarette. Accelerating the speed of nicotine delivery in ONPs might increase their misuse liability relative to cigarettes.

Levels of nicotine and tobacco-specific nitrosamines in oral nicotine pouches

BACKGROUND

Nicotine pouches without tobacco are new products that deliver nicotine into the body via the oral mucosa. There is a lack of independent research on the chemical composition and product characteristics of these products, contributing to uncertainties regarding product regulation. This study sought to address knowledge gaps by assessing levels of nicotine and screening for tobacco-specific nitrosamines (TSNAs) in a sample of these products.

METHODS

Nicotine pouches (n=44) and nicotine-free pouches (n=2) from 20 different manufacturers were analysed regarding their contents of nicotine and TSNAs by gas chromatography with flame ionisation and liquid chromatography-tandem mass spectrometry, respectively. Product labelling and pH values of aqueous extracts were determined.

RESULTS

Nicotine contents of products ranged from 1.79 to 47.5 mg/pouch; median product weight, pH, and proportion of free-base nicotine were 0.643 g, 8.8, and 86%, respectively. A clear labelling of the nicotine content was missing on 29 products and nicotine strength descriptions were ambiguous. TSNAs were detected in 26 products, with a maximum of 13 ng N-nitrosonornicotine/pouch.

CONCLUSION

Although nicotine pouches may potentially be a reduced risk alternative for cigarette smokers or users of some other oral tobacco products, nicotine contents of some pouches were alarmingly high. Presence of carcinogenic TSNAs in the nicotine pouches is of serious concern. Better manufacturing processes and quality control standards should be implemented. Labels of nicotine strength on most products are misleading. A strict regulation regarding nicotine contents and its labelling would be advisable.

Nicotinic receptors in airway disease

With continued smoking of tobacco products and expanded use of nicotine delivery devices worldwide, understanding the impact of smoking and vaping on respiratory health remains a major global unmet need. Although multiple studies have shown a strong association between smoking and asthma, there is a relative paucity of mechanistic understanding of how elements in cigarette smoke impact the airway. Recognizing that nicotine is a major component in both smoking and vaping products, it is critical to understand the mechanisms by which nicotine impacts airways and promotes lung diseases such as asthma. There is now increasing evidence that α7 nicotinic acetylcholine receptors (α7nAChRs) are critical players in nicotine effects on airways, but the mechanisms by which α7nAChR influences different airway cell types have not been widely explored. In this review, we highlight and integrate the current state of knowledge regarding nicotine and α7nAChR in the context of asthma and identify potential approaches to alleviate the impact of smoking and vaping on the lungs.

Characterization of physiochemical parameters & their effect on microbial content of smokeless tobacco products marketed in north India

BACKGROUND OBJECTIVES

Smokeless tobacco (SLT) product consumption has profound public health implications for its users. The p H and moisture of SLTs determine the bioavailability of nicotine, the microbial structure dynamics and the amount of microbial conversion of tobacco alkaloids to carcinogenic tobacco-specific nitrosamines. This study aimed to characterize and compare the p H, moisture and alkaloid content of various SLT products.

METHODS

Thirty-seven SLT samples including khaini , snus, moist snuff, gul , pan masala , zarda , Mainpuri kapoori and qiwam were collected from the retail market around the National Capital Region in north India and their p H, moisture, nicotine and alkaloid content were measured. The p H and total nicotine were used to calculate the amount of free nicotine, the readily absorbed form, for each product by applying the Henderson-Hasselbalch equation.

RESULTS

The investigation showed that the SLTs varied drastically in their p H (5.36 to 10.27), moisture content (4.7 to 51.7%) and alkaloid content (0.82 to 35.87 mg/g). The p H and free nicotine levels of a product were found to be positively correlated, and the highest free nicotine content was reported in snus samples. Further, the moisture content was seen to impact the bacterial and fungal diversity in these samples.

INTERPRETATION CONCLUSIONS

Studies to detect the presence of pathogenic microbiological genera as well as potentially toxic constituents are warranted. The use of SLTs as an alternative to cigarette smoking should be discouraged, and cessation programmes must call attention to their detrimental effects and emphasize on benefits of quitting SLT consumption.

Factors predicting willingness to quit snus and cigarette use among young males

The health hazards of smoking are well recognised and recently knowledge about the harmful effects of nicotine and snus is accumulating. We investigated the factors increasing the willingness of young Finnish males to quit snus and cigarette smoking. We conducted a questionnaire study conducted in 3 out of 16 Finnish Defence Forces units which included 6508 male conscripts, of whom 4706 responded (response rate 72%, mean age 19.4 years). Factors related to the willingness to quit use were analysed by ordinal regression models. Backward selection following the Akaike information criterion (AIC) was used for the model. The prevalence figures of daily snus use and smoking were 17% and 25%, respectively. 16% of the daily snus users were also daily smokers and 29% were occasional smokers. Multivariate analysis showed that the willingness to quit snus use was associated with the perception of health hazards (OR 3.09, 95% CI 1.94-4.93) and with ≥ 2 quit attempts (OR 3.63, 95% CI 2.44-5.40). The willingness to quit smoking was associated with ≥ 2 quit attempts (OR 3.22, 95% CI 2.32-4.49), and with advice to quit smoking (OR 1.65, 95% CI 1.17-2.32). We created a brief two-question assessment model for snus dependence. With this model, nicotine dependence of daily snus users was congruent with that of nicotine dependence of smokers. A direct comparison with serum cotinine levels is necessary before our assessment model can be used as a proxy for dependence. Regular snus use predisposes to nicotine addiction and accumulated health hazards. Our findings underscore the importance of health promotion efforts in early adolescence and of active support for quitting snus use. Easily applicable tools to estimate nicotine addiction are needed for everyday clinical use.

Oral nicotine pouches with an aftertaste? Part 1: screening and initial toxicological assessment of flavorings and other ingredients

Nicotine pouches are oral products that deliver nicotine without containing tobacco. Previous studies mainly focused on the determination of known tobacco toxicants, while yet no untargeted analysis has been published on unknown constituents, possibly contributing to toxicity. Furthermore, additives might enhance product attractiveness. We therefore performed an aroma screening with 48 different nicotine-containing and two nicotine-free pouches using gas chromatography coupled to mass spectrometry, following acidic and basic liquid-liquid extraction. For toxicological assessment of identified substances, European and international classifications for chemical and food safety were consulted. Further, ingredients listed on product packages were counted and grouped by function. Most abundant ingredients comprised sweeteners, aroma substances, humectants, fillers, and acidity regulators. 186 substances were identified. For some substances, acceptable daily intake limits set by European Food Safety Agency (EFSA) and Joint FAO/WHO Expert Committee on Food Additives are likely exceeded by moderate pouch consumption. Eight hazardous substances are classified according to the European CLP regulation. Thirteen substances were not authorized as food flavorings by EFSA, among them impurities such as myosmine and ledol. Three substances were classified by International Agency for Research on Cancer as possibly carcinogenic to humans. The two nicotine-free pouches contain pharmacologically active ingredients such as ashwagandha extract and caffeine. The presence of potentially harmful substances may point to the need for regulation of additives in nicotine-containing and nicotine-free pouches that could be based on provisions for food additives. For sure, additives may not pretend positive health effects in case the product is used.

Physical and chemical characterization of smokeless tobacco products in India

The rapid proliferation of smokeless tobacco (SLT) in India has occurred without adequate information on the possible dangers and toxicity of these products. Tobacco flavors as well as nicotine (both protonated and un-protonated) are responsible for health dangers and addiction. The study aimed to offer information on the physical characteristics of commonly used smokeless tobacco products (including microscopic analysis), along with nicotine content (both total and un-protonated), pH, moisture, and flavors. The Standard Operating Procedures (SOPs) validated by the World Health Organization (WHO) recognized Tobacco Testing Laboratory TobLabNet) were applied for the analysis of various constituents of the SLTs. The microscopic analysis indicated that some of the SLT products like khaini were finely processed and available in filter pouches for users' convenience and prolonged use leading to prolonged retention and addiction potential. Nicotine absorption and availability (both protonated and un-protonated) are affected by moisture and pH. Essences provide a pleasant aroma and flavor, with an increased risk of misuse and other health problems. Few chewing tobacco and Zarda had the lowest levels of un-protonated nicotine (0.10-0.52% and 0.15-0.21%, respectively), whereas Gul, Gudhaku, and Khaini had the highest levels, ranging from 95.33 to 99.12%. Moisture and pH ranged from 4.54 to 50.19% and 5.25-10.07 respectively. Menthol (630.74-9681.42 µg/g) was the most popular flavour, followed by Eucalyptol (118.16-247.77 µg/g) and camphor (148.67 and 219.317 µg/g). SLT's health concerns and addiction dangers are exacerbated by the high proportion of bioavailable nicotine coupled with flavors. The findings of this study have important implications for the regulation and use of SLT in countries where use of SLT is prevalent.

A Comparison of Use Topography and Nicotine Pharmacokinetics Among Loose and Portioned Smokeless Tobacco Users

INTRODUCTION

Moist snuff smokeless tobacco (ST) products are available in the United States in both "loose" and "portioned" (ie, pouched) formats, but no published study to date has clinically evaluated the associations between ST format, use behavior, and nicotine exposure.

AIMS AND METHODS

Participants used their usual brand of ST (loose ST [n = 30] or portioned ST [n = 20]) during an experimental visit wherein use behavior and plasma nicotine pharmacokinetic parameters were measured following single use (first hour of the session) and ad libitum use (remaining 7 h of the session). Participants' ST products were chemically characterized prior to use for pH and nicotine content.

RESULTS

The average amount per use (2.99 vs. 1.52 g; p = .005) and total amount used (11.45 vs. 5.4 g; p = .002) were significantly higher among the loose ST group. Maximum plasma nicotine concentration (Cmax; 33.4 vs. 19.1 ng/ml) and area under the nicotine concentration versus time curve (AUC) were significantly higher for the loose ST group for the first hour (1474.8 vs. 807.2 min* ng/ml; p = .003) and throughout the 8-hour session (15827.9 vs. 8155.3 min* ng/ml; p < .001). Significant associations were observed between free nicotine content and first use Cmax (rs = .488, loose ST group) and AUC0-1 h (rs = 0.448, loose ST group; rs = .441, portioned ST group).

CONCLUSIONS

The loose ST group used more product and had a greater average deposition time per use than the portioned ST group. Nicotine exposure was more strongly associated with free nicotine content than total nicotine content.

IMPLICATIONS

To our knowledge, the current investigation was the first study to date to clinically evaluate the associations between usual-brand smokeless format, use behavior, and nicotine exposure. We observed meaningful differences in use behavior and subsequent nicotine exposure between loose and portioned ST users. Further, we observed that nicotine exposure was more strongly associated with free nicotine content than total nicotine content.

Fungal Community Composition and Function Associated with Loose Smokeless Tobacco Products

Smokeless tobacco products (STPs) contain several microbial communities which are responsible for the formation of carcinogens, like tobacco-specific nitrosamine (TSNAs). A majority of STPs are sold in loose/unpackaged form which can be loaded with a diverse microbial population. Here, the fungal population and mycotoxins level of three popular Indian loose STPs, Dohra, Mainpuri Kapoori (MK), and loose leaf-chewing tobacco (LCT) was examined using metagenomic sequencing of ITS1 DNA segment of the fungal genome and LC-MS/MS, respectively. We observed that Ascomycota was the most abundant phylum and Sterigmatomyces and Pichia were the predominant fungal genera in loose STPs. MK displayed the highest α-diversity being enriched with pathogenic fungi Apiotrichum, Aspergillus, Candida, Fusarium, Trichosporon, and Wallemia. Further, FUNGuild analysis revealed an abundance of saprotrophs in MK, while pathogen-saprotroph-symbiotroph were abundant in Dohra and LCT. The level of a fungal toxin (ochratoxins A) was high in the MK product. This study caution that loose STPs harbor various harmful fungi that can infect their users and deliver fungal toxins or disrupt the oral microbiome of SLT users which can contribute to several oral pathologies.

Nicotine pouches: a summary of regulatory approaches across 67 countries

INTRODUCTION

Nicotine pouches are small, permeable pouches containing nicotine. The nicotine may either be derived from tobacco plants or synthetically produced. Nicotine pouches are available worldwide, but little is known as to how various countries regulate these products. This study summarises nicotine pouch regulatory policies across 67 countries.

METHODS

This research summarises insights obtained through active policy surveillance work in which we requested information on the availability of nicotine pouches and applicable policies and analysed responses from representatives of 67 countries (representatives included subject matter experts in government or civil society organisations). These countries span all WHO regions.

RESULTS

We found significant variation in how countries classify nicotine pouches, with many countries' current regulatory approach failing to regulate nicotine pouches that used synthetic nicotine. We found 34 countries regulate nicotine pouches with 23 of these countries' policies encompassing synthetic nicotine. Countries regulating both synthetic and tobacco-derived nicotine pouches generally (1) rely on existing policies for tobacco products and/or medicines or (2) have developed new policies or regulatory classifications that specify nicotine as the substance at issue rather than linking policies solely to tobacco.

CONCLUSION

Our work offers novel insight into nicotine pouch markets and national regulatory approaches. Policy approaches vary from not regulating nicotine pouches at all to banning both forms of nicotine pouches. Policies used by countries regulating both tobacco-derived and synthetic nicotine pouches offer a roadmap for how other jurisdictions can add effective guardrails to the use of these and other non-medicinal nicotine products.

Nicotine pharmacokinetics and subjective responses after using nicotine pouches with different nicotine levels compared to combustible cigarettes and moist smokeless tobacco in adult tobacco users

RATIONALE

Oral tobacco-derived nicotine products include on!® nicotine pouches (NPs) which are tobacco-leaf free and available in multiple flavors and nicotine levels. Switching completely to NPs from cigarettes and moist smokeless tobacco (MST) has the potential to reduce harm for adult tobacco consumers. However, the dependence potential of NPs is not established. Therefore, we characterized the abuse potential of NPs with different nicotine levels compared to cigarettes and MST.

OBJECTIVES

To evaluate nicotine pharmacokinetics (PK) and subjective effects of NPs (ranging from 1.5 to 8 mg nicotine) compared to own brand cigarettes (OBCs) and MST (OBMST).

METHODS

We used a randomized, in-clinic, partial single-blind, 7-way crossover design to assess nicotine PK and subjective effects in dual users of cigarettes and MST.

RESULTS

The mean nicotine Cmax for NPs increased with nicotine level, ranging from 3.5 ng/mL (1.5 mg NP) to 15.4 ng/mL (8 mg NP), compared with 12.2 ng/mL for OBCs and 9.8 ng/mL for OBMST. Nicotine tmax was much longer for all NPs and OBMST (32.5-34.4 min) compared to OBCs (8.5 min). Reductions in urges to smoke after use of the 2 mg, 3.5 mg, and 8 mg NPs were not statistically different (p > 0.05) relative to OBC. Also, NPs resulted in lower ratings of positive subjective effects relative to OBCs and OBMST.

CONCLUSIONS

Overall, based on the study results and literature reported nicotine PK values for cigarettes and MST, the abuse potential of NPs is not likely to be higher than OBCs and OBMST. NPs may be potentially acceptable switching products for users of cigarettes and MST products.

Formulation of Smokeless Tobacco Products with a Wide Range of pH to Study Nicotine Pharmacokinetics and Pharmacodynamics

The rate of nicotine absorption from tobacco products is a determinant of addiction potential and other detrimental health effects. Oral nicotine bioavailability from moist snuff smokeless tobacco (ST) is influenced by nicotine content, pH, flavors, and tobacco cut. For use in a clinical study testing the effect of pH on nicotine pharmacokinetics, four investigational ST products that differed only in pH were produced. A commercial ST product (Copenhagen Long Cut Original, pH 7.7) was modified with citric acid monohydrate (23 mg/g tobacco) or sodium carbonate (4.6 and 11 mg/g) to create products with pH 5.0, 8.2, and 8.6, respectively. All products - including the original product with pH 7.7 - were individually packaged (approximately 2g) in aluminum foil pouches and stored frozen (-20 °C); pH, nicotine, tobacco-specific nitrosamines, moisture content, and mold and yeast counts were tested for up to 19 months to verify stability. Remarkable stability was demonstrated in this packaging/storage combination. For example, pH from all products were within 0.1 pH units and never exceeded 0.2 units. Nicotine concentration averaged 9.07 mg/g at baseline, maximal deviations from baseline in the four products averaged 0.30 mg/g. Similarly, TSNA, moisture content, yeast, and mold did not materially change. This study illustrates a method of investigational tobacco products formulation by manipulating a single design feature (or component) with the purpose of independently and systematically assessing its influence on nicotine bioavailability in a clinical study.

Toxic effects of smokeless tobacco on female reproductive health: A review

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Smokeless tobacco use can lead to impairments of ovarian function, morphology, oocyte quality and hormonal regulation.

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Use of smokeless tobacco during pregnancy has adverse health effects on both the mother and fetus.

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Exposure to smokeless tobacco in utero has long term health consequences on offspring.

The habitual consumption of tobacco in its various form is widespread and a serious public health issue globally. In particular, the use of smokeless tobacco has increased substantially due to its easy availability and misconception that it is relatively harmless compared to smoking. Tobacco use has been well established from numerous studies as a causative agent of devastating illnesses such as cancer, insulin resistance, hypertension, acute respiratory disease, osteoporosis, etc. Limited but growing evidence have also suggested its role in adversely affecting reproductive capabilities and outcomes in women of reproductive age and during pregnancy. This paper provides an updated review on available literature regarding the negative effects of smokeless tobacco use on female reproductive health, during pregnancy and its adverse consequences on the offspring. Existing data suggests the association between chronic smokeless tobacco use and impairment of ovarian morphology and function, oocyte quality, hormonal perturbations, fetal development and long-term health effects on the fetus. Improved understanding of these issues can contribute to better awareness of the dangers of smokeless tobacco products.

The pH of Smokeless Tobacco Determines Nicotine Buccal Absorption: Results of a Randomized Crossover Trial

Nicotine absorption rate influences tobacco products' addictiveness. For smokeless tobacco, nicotine buccal absorption is associated with its free-base form; the pH of smokeless tobacco defines the proportion of free-base (i.e., unprotonated) vs. protonated nicotine. This was the first study to compare nicotine pharmacokinetics (PK) and pharmacodynamics (PD) after the use of commercial smokeless tobacco products that were experimentally manipulated to differ only in pH and percent free-base nicotine. Moist snuff users (N = 40) completed four crossover visits and used a single 2 g portion of Copenhagen Original Long Cut amended to 4 pH levels: 5.0, 7.7, 8.2, and 8.6 (free-base nicotine 0.1, 32, 60, and 79%) for 30 minutes. Nicotine PK and PD were assessed for 4 hours post-use. Nicotine PK substantially depends on its free-base proportion, with more than 4-fold increases in mean plasma nicotine maximum concentration and area under the curve over 240 minutes (3.9 to 16.7 ng/mL; 385 to 1810 ng min/mL, respectively, both P < 0.001) from pH 5.0 to 8.6. The autonomic cardiovascular effects of smokeless tobacco use reflected percent free-base nicotine, with small (albeit significant) systematic increases in heart rate and blood pressure associated with free-base nicotine. Smokeless tobacco product pH and percent free-base nicotine play a major role in the rate and extent of nicotine absorption, determining product PD effects and abuse potential. Research and regulation of smokeless tobacco products should consider both total nicotine content and product pH. Further research may address the impact of modifying pH on the addictiveness of smokeless tobacco and associated use behaviors.

Evaluation of Flavor Effects on Oral Nicotine Liking and/or Disliking Using the Taste Reactivity Test in Rats

INTRODUCTION

Tobacco product flavors may change the sensory properties of nicotine, such as taste and olfactory cues, which may alter nicotine reward and aversion and nicotine taking behavior. The hedonic or aversive value of a taste stimulus can be evaluated by examining affective orofacial movements in rodents.

AIMS AND METHODS

We characterized taste responses to various oral nicotine concentrations using the taste reactivity test in rats. We also evaluated the impact of menthol and benzaldehyde (cherry, almond) flavorants on both ingestive and aversive responses to oral nicotine. Adult Sprague-Dawley rats (n = 5-10 per sex per group) were implanted with intraoral catheters and received 20 infusions (200 µl/ea). Nicotine (1-100 µg/mL) was evaluated in taste reactivity test to determine taste responses to nicotine. Later, the effects of menthol (50 µg/mL) and benzaldehyde (100 µg/mL) on the taste responses to nicotine were determined.

RESULTS

Nicotine at low concentrations (3 µg/mL in males, 1 µg/mL in females) elicited significantly greater ingestive responses compared with water, whereas higher nicotine concentrations (≥30 µg/mL in males, ≥10 µg/mL in females) elicited significant aversive reactions. Thus, intraoral nicotine induced both hedonic and aversive responses in a concentration- and sex-dependent manner. Females were more sensitive to nicotine's concentration. The addition of menthol or benzaldehyde significantly increased the hedonic responses to nicotine, and significantly decreased the aversive nicotine responses.

CONCLUSIONS

Oral nicotine induces both hedonic and aversive taste responses, which may represent liking and disliking. Menthol and benzaldehyde can alter the orosensory experience of nicotine, which may influence nicotine's abuse liability.

IMPLICATIONS

Our work represents a model to study impact of flavors on oral nicotine liking and disliking responses in rats. Moreover, our findings show that menthol and benzaldehyde alter the orosensory experience of nicotine, suggesting that both could influence nicotine's abuse liability.

Nicotine pharmacokinetics and subjective response among adult smokers using different flavors of on!® nicotine pouches compared to combustible cigarettes

RATIONALE

on!® nicotine pouches (NPs) are oral tobacco-derived nicotine products that are tobacco-leaf free and are available in a variety of flavors and nicotine strengths. Switching completely to NPs from cigarettes may present the potential to reduce harm in adult smokers (AS) unable or unwilling to quit smoking. We characterized the abuse potential of six different flavor variants of NPs compared to cigarettes.

OBJECTIVES

The objective of this study was to evaluate the nicotine pharmacokinetics (PK) and subjective effects of different flavor variants of NPs compared to participants' own brand cigarettes (OBCs) in AS.

METHODS

In this single-blind, randomized, 7-way crossover study, we assessed nicotine PK, subjective measures (using well-established questionnaires), and product use behavior associated with six flavors of 4 mg NPs and OBCs in AS that remained in clinic for the duration of the test period.

RESULTS

Nicotine C_max values ranged from 9.0 to 11.5 ng/mL for the NPs and 16.3 ng/mL for OBCs. The t_max ranged from 30.1 to 34.9 min for ONPs and 7.5 min for OBCs. Use of NPs resulted in lower ratings of urge to smoke or craving a cigarette. All the NPs were considered pleasant, but not as much as OBCs. Flavor did not appear to influence the nicotine PK or subjective responses.

CONCLUSIONS

Based on the nicotine PK parameters and subjective responses, we conclude that NPs, regardless of flavor, likely have lower abuse potential than cigarettes. Overall, this study suggests that the NPs may be potentially acceptable switching products for adult smokers.

Prevalence, duration of exposure and predicting factors for snus use among young Finnish men: a cross-sectional study

OBJECTIVE

The health hazards of tobacco products depend on the level of exposure, but little is known about the characteristics of snus use. The aim of this study was to investigate the duration of daily exposure to snus among occasional and daily users and its associated predictive factors among young Finnish men.

DESIGN

Cross-sectional questionnaire study.

SETTING

Three out of 16 Finnish Defence Forces units.

PARTICIPANTS

1280 young Finnish male conscripts starting their military service in 2016 chosen by simple random sampling.

PRIMARY AND SECONDARY MEASURES

The prevalence, duration of use and the amount of daily usage of snus and cigarettes were investigated. The attitudes towards perceived harmfulness of snus and the predictive factors affecting the total time of snus consumption were examined.

RESULTS

Almost a fifth (19.5%) of the conscripts reported daily snus use, and a further 16% reported occasional use. Daily snus use was associated with an earlier starting age, longer duration of use and higher daily exposure time compared with occasional use. On average, daily snus users consumed 10 portions and occasional users three portions per day (p<0.001). The daily total exposure time for daily users was 372 min (95% CI 344 to 401) and for occasional users 139 min (95% CI 106 to 171). Respondents with an upper secondary education had significantly less daily total exposure than those with basic comprehensive education (p=0.036). Perceptions of snus as a harmful substance resulted in a significantly lower duration of exposure.

CONCLUSION

Snus use was very common among young Finnish men. High snus exposure duration was associated with an earlier starting age, a longer history of use and a careless attitude to its health hazards. A higher education level was a protective factor for total exposure time. Studies of the long-term health effects and dependency profile of snus use are needed.

Characterization of Total and Unprotonated (Free) Nicotine Content of Nicotine Pouch Products

INTRODUCTION

Nicotine pouch products, oral smokeless products that contain nicotine but no tobacco leaf material, have recently entered the US marketplace. Available data indicate sales of these products in the United States have increased since 2018; however, the extent of use among US youth and adults is uncertain.

METHODS

To assay the chemistry of these emerging tobacco products, we analyzed 37 nicotine pouch brands from six total manufacturers. Almost all of the products had flavor descriptors (36 of 37), such as mint, licorice, coffee, cinnamon, and fruit. The amount of free nicotine, the form most easily absorbed, was calculated for each product using total nicotine, product pH, the appropriate pKa, and the Henderson-Hasselbalch equation.

RESULTS

Nicotine pouch products varied in pouch content mass, moisture content (1.12%‒47.2%), alkalinity (pH 6.86‒10.1), and % free nicotine (7.7%‒99.2%). Total nicotine content ranged from 1.29 to 6.11 mg/pouch, whereas free nicotine ranged from 0.166 to 6.07 mg/pouch. These findings indicate that nicotine and pH levels found in some of these nicotine pouches are similar to conventional tobacco products, such as moist snuff and snus, and that most of these pouch products are flavored.

CONCLUSIONS

Although these products likely lack many tobacco-related chemicals, each product analyzed contained nicotine, which is both addictive and can harm human health. Given that nicotine pouches may appeal to a spectrum of users, from novice to experienced users, it is important to include these emerging tobacco products in tobacco control research, policy, and practice.

IMPLICATIONS

These "tobacco-free" nicotine pouches have similar pH and nicotine content to conventional tobacco products, such as moist snuff and snus. Although they lack many tobacco-related chemicals, most are highly flavored which could increase experimentation from new users. Given that nicotine pouches may appeal to a spectrum of users, from novice to experienced users, in terms of their flavors and nicotine content, it is important to examine and include these emerging tobacco products as they relate to tobacco control research, policy, and practice.

Effects of Oral pH Changes on Smoking Desire

BACKGROUND

Nicotine addiction is associated with nicotine absorption from the buccal mucosa, and it is stated that the main factor that determines nicotine absorption is saliva pH. In the literature, the effects of changes in saliva pH values after eating and drinking on smoking desire in smokers were not questioned.

AIM

To show the effect of saliva pH changes on smoking desire. The secondary aim was to show the impact of coffee and water drinking on saliva pH and smoking on oral-dental health (oral hygiene and gingival bleeding).

STUDY DESIGN

Case-control study.

METHODS

A questionnaire was administered that included "Sociodemographic Data Form" and smoking history and Fagerström Test for Nicotine Dependence (FTND). Oral and dental examinations were performed with mirror sonds and using oral hygiene standard Silness and Leöe plaque index and DMFT Index (Index of Decayed Missing or Filled Teeth). Untreated saliva samples were taken, and baseline saliva flow rate and pH values were measured. To assess pH changes, saliva pH was remeasured after sugar-free instant coffee and water consumption. Smoking desire was evaluated with the Visual Analog Scale (VAS).

RESULTS

In this study, 24 (55.8%) females and 19 (44.2%) males were among the 43 smoking and 39 nonsmoking cases. Smoking was significantly associated with poor oral hygiene (in smokers 4.71 (±1.40), in non-smokers 2.30 (±1.59); P < .01). DMFT index was higher in smokers than in non-smokers (in smokers 6.45 (±3.69), in non-smokers 3.87 (±2.67); P < .01). Gingival bleeding was more prevalent in smokers (0.68 (±0.76)) than non-smokers (1.20 (±0.90); P = .009). Salivary flow rates were lower in smokers (in smokers 2.56 (±1.34), in non-smokers 3.00 (±1.22), P = .06). In both groups, pH values increased after coffee consumption and decreased after water; in smokers basal: 6.67 (±0.41), pH coffee: 6.93 (±0.36), pH water: 6.85 (±0.33); in non-smokers pH basal: 6.84 (±0.37), pH coffee: 7.02 (±0.37), pH water: 6.97 (±0.31), P < .01. The VAS values of smokers at basal 4.73 (±3.21); P < 0.01, after coffee consumption 4.91 (±3.08); P < .01, and after water 3.15 (±2.72); P < .01.

CONCLUSION

The saliva pH increased after coffee consumption and decreased after drinking water. Besides, VAS values decreased significantly after drinking water. The results suggest that a simple behavior such as drinking water may be used in conjunction with behavioral and cognitive therapies to pursue smoking cessation.

Particle size penetration rate and effects of smoke and smokeless tobacco products - An invitro analysis

Utilization of tobacco products is a global epidemic that causes a health threat among the adolescents and adults of the world. If the current pattern perpetuates, it is estimated to cause 10 million deaths each year by 2020. According to the 2009-2010 survey by Global Adult Tobacco Survey, 53.5% of Indians use tobacco products (66.2% of men and 40% of women). Cancers of the lip and oral cavity are highly frequent in Southern Asia (eg: India and Sri Lanka) and it is also the leading cause of cancer death among men in India and Sri Lanka.

AIM AND OBJECTIVES

The aim of the study is to evaluate the particle size, and assess the penetration rate in egg shell membrane and proliferation rate using cell lines among 4 commercially available tobacco products.

MATERIALS AND METHODS

A total of 4 tobacco product samples namely Gutka, Khaini, Beedi and Cigarette was used to analyse the particle size using High resolution Scanning electron microscopy, the penetration rate on egg shell membrane using Spectroflurometry and proliferative rate using ELISA on cell lines respectively.

RESULTS

Khaini revealed the smallest particle size and highest penetration and proliferation rate compared to Gutka, Beedi and Cigarette.

CONCLUSION

Current evidence shows that individuals who consume Khaini are at high risk to develop potentially malignant disorders and oral squamous cell carcinoma when compared to Gutka, Beedi and Cigarette (in the order of occurrence).

More than Smoke and Patches: The Quest for Pharmacotherapies to Treat Tobacco Use Disorder

Tobacco use is a persistent public health issue. It kills up to half its users and is the cause of nearly 90% of all lung cancers. The main psychoactive component of tobacco is nicotine, primarily responsible for its abuse-related effects. Accordingly, most pharmacotherapies for smoking cessation target nicotinic acetylcholine receptors (nAChRs), nicotine's major site of action in the brain. The goal of the current review is twofold: first, to provide a brief overview of the most commonly used behavioral procedures for evaluating smoking cessation pharmacotherapies and an introduction to pharmacokinetic and pharmacodynamic properties of nicotine important for consideration in the development of new pharmacotherapies; and second, to discuss current and potential future pharmacological interventions aimed at decreasing tobacco use. Attention will focus on the potential for allosteric modulators of nAChRs to offer an improvement over currently approved pharmacotherapies. Additionally, given increasing public concern for the potential health consequences of using electronic nicotine delivery systems, which allow users to inhale aerosolized solutions as an alternative to smoking tobacco, an effort will be made throughout this review to address the implications of this relatively new form of nicotine delivery, specifically as it relates to smoking cessation. SIGNIFICANCE STATEMENT: Despite decades of research that have vastly improved our understanding of nicotine and its effects on the body, only a handful of pharmacotherapies have been successfully developed for use in smoking cessation. Thus, investigation of alternative pharmacological strategies for treating tobacco use disorder remains active; allosteric modulators of nicotinic acetylcholine receptors represent one class of compounds currently under development for this purpose.

Characteristics of "American Snus" and Swedish Snus Products for Sale in Massachusetts, USA

Introduction

Snus may present lower health risks than cigarettes, but its harm reduction potential may be undermined if used dually with cigarettes. The likelihood of exclusive snus use compared with dual use may depend in part on the capacity of snus to deliver nicotine in doses that are satisfactory to smokers. We examined characteristics of "American snus" products, including nicotine levels, and compared to snus products that are more typical of Sweden.

Methods

Tobacco industry reports for snus products submitted to the Massachusetts Department of Public Health for the year 2014 were used to assess moisture (%), pH, total nicotine, and unionized (free) nicotine (both mg/g and percent of total). A total of 14 ("American") snus products made by American manufacturers Philip Morris USA (n = 6), R.J. Reynolds Tobacco Company (n = 6), and US Smokeless Tobacco Company (n = 2), were compared with Swedish-style ("Swedish") snus products (n = 10) made by Swedish Match North America.

Results

Compared with Swedish snus, American snus brands contained significantly lower concentrations of unionized nicotine (median: 0.52 mg/g vs. 6.52 mg/g; p < .001) and proportion of unionized nicotine (median: 3.17% vs. 81.8%; p < .001). American snus brands also had significantly lower pH (median: 6.54 vs. 8.68; p < .001) and moisture (median: 30.3% vs. 53.4%; p < .001).

Conclusions

Swedish-made snus has higher unionized nicotine, measured by concentration and proportion of total nicotine, compared with snus products made by American manufacturers. These findings suggest that American snus products have lower addiction potential than Swedish snus, and may be more likely to be used dually with cigarettes than as a sole source of nicotine.

Implications

American snus products contain significantly lower unionized nicotine, lower pH, and lower moisture, compared with Swedish snus products. Snus addiction potential and patterns of usage, including co-use with cigarettes, may differ between American and Swedish snus products due to differences in snus product characteristics.

Factors effecting the induction of rat forestomach hyperplasia induced by Swedish oral smokeless tobacco (snus)

Long term exposure to oral smokeless tobacco may induce lesions in the oral cavity characterized by a hyperplastic epithelium. The possible role of nicotine and the physical properties of oral tobacco for developing these lesions, as well as of dysplasia and neoplasia is unclear. Low nitrosamine Swedish snus as well as non-genotoxic butylated hydroxyanisole induces increased cellular proliferation in the rat forestomach epithelia. Using this model, we report here on the effects of nicotine, pH, and particle size. Snus with different properties had no impact on oxidative stress as determined by 8-oxo-7,8-dihydro-2'-deoxyguanosine, or on interleukin IL-1b. Whereas BHA boosted IL-6, probably due to the presence of nicotine. there was no significant enhancement of cell divisions with increasing particle size, although in individual samples the variations in proliferation rates increased greatly with increasing particle size. Conforming to human experience, the enhanced cell proliferation caused by snus was found to be completely reversible. A cacao bean extract had a protective action similar to that previously found for blueberries. The main cause of the observed tobacco induced cell proliferation could be mechanical irritation, possibly in combination with nicotine, whereas within the studied range, pH did not affect the rate of cell division.

Regulation of toxic contents of smokeless tobacco products

Effective regulation of contents of tobacco products is one of the primary milestones to reduce negative health effects associated with the use of smokeless tobacco (SLT) products. As per the available sources, testing of some SLT products has been done on ad hoc basis, but there is a lack of comprehensive and periodic analysis of these products. In addition, the available results indicate huge variations among the levels of pH, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, N-nitrosonornicotine, benzo[a]pyrene, heavy metals and nicotine within different products as well as within different brands of the same product. This review was aimed to throw light on the variations and gaps in testing of SLT products and emphasize the need for strong policy regulation for monitoring the chemical constituents of these products.

Nicotine delivery and pharmacologic response from Verve, an oral nicotine delivery product

Verve, an oral nicotine delivery product (ONDP), was introduced by Nu Mark (Altria Client Group, Richmond VA) for smokers to use in places where smoking is prohibited. This study assessed the effect of this ONDP on plasma nicotine levels, heart rate, product satisfaction, and ability to suppress smoking urge and cigarette cravings. Thirteen daily cigarette smokers [8 men and 5 women; average age 33.4years] attended two laboratory sessions, one occurred after overnight tobacco abstinence. Plasma samples were collected before and after ONDP use and measured for nicotine. In non-abstinent smokers, mean plasma nicotine levels increased from 18.3 to 21.0ng/mL. In abstinent smokers, average nicotine levels increased from 3.1 to 4.5ng/mL. After overnight tobacco abstinence, ONDP use significantly (p<0.01) increased heart rate from 69beats per minute (bpm) to 75bpm; while urge to smoke decreased significantly (p<0.01) from a score of 8.6 to 4.9. Participants indicated moderate product satisfaction that was not changed by tobacco abstinence. Analysis of unused ONDP revealed total nicotine levels of 1.68±0.09mg/disc. Spent ONDP discs were also analyzed to determine % nicotine liberated during chewing; results were 80% in the non-abstinent and 82% in the abstinent conditions (ns). Our study results indicate that ONDP use can increase plasma nicotine levels and heart rate and reduce cigarette cravings in abstinent smokers.