Nicotine gum: chew rate, subjective effects and plasma nicotine

Characterization of the Abuse Potential in Adult Smokers of a Novel Oral Tobacco Product Relative to Combustible Cigarettes and Nicotine Polacrilex Gum

Novel noncombustible tobacco products offer adult smokers (ASs) alternatives to combustible cigarettes lower on the continuum of risk; however, the abuse potential of such products has not been well studied. The objective of this study was to evaluate the abuse potential of 2 chewable tobacco‐derived nicotine containing products, VERVE Chews Blue Mint (test 1) and Green Mint (test 2), in ASs compared with own‐brand cigarettes (CIGS) and nicotine polacrilex gum (GUM) using subjective measures and nicotine pharmacokinetics. ASs used the test products during a 5‐day at‐home trial prior to completing an in‐clinic 4‐period randomized crossover study. During the study ASs used test products, CIGS, and GUM once on separate days. Responses to Tobacco/Nicotine Withdrawal and Direct Effects of Product questionnaires were documented, and blood samples were collected to assess nicotine pharmacokinetics during each product use. Nicotine pharmacokinetic parameters (C_max and AUC) were statistically significantly lower with use of test products compared with CIGS and statistically significantly higher compared with GUM. No appreciable differences were noted between the 2 flavors for any of the end points measured. Reductions in maximum urge to smoke and maximum responses to the question “Is the Product ‘Pleasant’ Right Now?” for the test products were statistically significantly lower than CIGS but comparable to GUM. Similar results were observed for responses to other items in the 2 questionnaires. The test products, under the conditions of this study, carry lower abuse potential than own‐brand cigarettes and similar to nicotine polacrilex gum.

Medicated Chewing Gums: Recent Patents and Patented Technology Platforms

The reason that the oral route attained such acceptance may be ascribed to its affluence of administration. Over the years, patient convenience- oriented exploration in the area of drug delivery has introduced potential innovative medicine delivery systems. The elegant drug delivery system is an amalgamation of science and dexterity with therapeutic prospect and presentability. It involves the administration of medications in a groundbreaking fashion with the assistance of cosmetics, wearable devices and oral drug delivery system which can also be used for ornamental purposes. Out of which, therapeutic chewing gum offers a highly suitable and amenable technique of dosing medications comprising children and elderlies. It is a potentially convenient means of administering medications either locally or systematically via the oral cavity. It bids innumerable gains over conventional drug delivery methods. Moreover, medicinal chewing gums involve the dynamic and constant masticatory actions for drug release. Currently, enriched expertise has made it promising to advance and fabricate medicated chewing gum with predefined properties and it could be a marketable triumph in the future. Apprehending this, several investigators and pharmaceutical companies are now engaged in developing innovative practices vis-à-vis medicated chewing gums by filing several patents in this area. The present manuscript also delivers a gestalt of various patented technology platforms based on different methods/mechanisms employed for the preparation of medicated chewing gums.

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.

Chewing gum increases energy expenditure before and after controlled breakfasts

Chewing has been associated with improved satiation and satiety, but little is known about the metabolic impact of gum chewing. We tested the hypothesis that gum chewing would increase energy expenditure (EE) and reduce respiratory exchange ratio (RER) before and after a controlled test meal. Seventeen males and 13 females (age 21.5 ± 6.6 years, body mass index 23.9 ± 2.8 kg/m(2)) participated in a randomized crossover study in which subjects chewed sugar-free gum for a total of 1 h (3 sessions of 20 min) on the test day (GC) and did not chew gum on a control day (NG). EE and RER were measured by indirect calorimetry after an overnight fast. Subjects consumed a breakfast shake containing 30% of their measured energy needs, and then postprandial EE and RER were measured for 3 h. Blood glucose (GLC) was measured in the fasting and postprandial states at regular intervals. Fasting EE was higher during GC (1.23 ± 0.04 kcal/min; 1 kcal = 4.2 kJ) than during NG (1.17 ± 0.04 kcal/min; p = 0.016). Postprandial EE was also higher during GC (1.46 ± 0.05 kcal/min) than during NG (1.42 ± 0.05 kcal/min; p = 0.037). Fasting and postprandial RER and GLC did not differ between GC and NG. The findings demonstrate that GC is associated with higher fasting and postprandial EE without altering blood glucose or substrate oxidation as measured by RER. These data suggest that gum chewing potentially could influence short-term energy balance in this population; however, longer-term research is needed.

Human brain functional network changes associated with enhanced and impaired attentional task performance

How is the cognitive performance of the human brain related to its topological and spatial organization as a complex network embedded in anatomical space? To address this question, we used nicotine replacement and duration of attentionally demanding task performance (time-on-task), as experimental factors expected, respectively, to enhance and impair cognitive function. We measured resting-state fMRI data, performance and brain activation on a go/no-go task demanding sustained attention, and subjective fatigue in n = 18 healthy, briefly abstinent, cigarette smokers scanned repeatedly in a placebo-controlled, crossover design. We tested the main effects of drug (placebo vs Nicorette gum) and time-on-task on behavioral performance and brain functional network metrics measured in binary graphs of 477 regional nodes (efficiency, measure of integrative topology; clustering, a measure of segregated topology; and the Euclidean physical distance between connected nodes, a proxy marker of wiring cost). Nicotine enhanced attentional task performance behaviorally and increased efficiency, decreased clustering, and increased connection distance of brain networks. Greater behavioral benefits of nicotine were correlated with stronger drug effects on integrative and distributed network configuration and with greater frequency of cigarette smoking. Greater time-on-task had opposite effects: it impaired attentional accuracy, decreased efficiency, increased clustering, and decreased connection distance of networks. These results are consistent with hypothetical predictions that superior cognitive performance should be supported by more efficient, integrated (high capacity) brain network topology at greater connection distance (high cost). They also demonstrate that brain network analysis can provide novel and theoretically principled pharmacodynamic biomarkers of pro-cognitive drug effects in humans.

Relationship Between Plasma and Oral Fluid Nicotine Concentrations in Humans

The relationship between plasma and oral fluid concentrations of nicotine after infusion at varying times was investigated. Five healthy human volunteers were administered 0, 0.75, and 1.5 mg nicotine as 0.5-, 1.0-, 2.5-, and 5-minute infusions. Blood and oral fluid were collected before drug administration and for 4 hours thereafter. Nicotine concentrations were determined by HPLC using a limit of quantification of 1 ng/mL. Plasma nicotine concentrations were dose related. Peak plasma concentrations (mean+/-SD) at the 4 infusion times were 14.1+/-5.5, 11.8+/-5.3, 12.8+/-1.9, and 11.5+/-4.0 ng/mL (N=5) after the 0.75-mg dose and 26.3+/-11.7, 19.3+/-12.8, 24.54+/-10.4, and 19.02+/-6.5 ng/mL after the 1.5-mg dose. In general, the highest peak concentration occurred at the shortest infusion time at each dose. Peak nicotine oral fluid concentrations (mean+/-SD) at the 4 infusion times of 22.4+/-29.1, 22.64+/-29.9, 19.1+/-13.5, and 49.1+/-31.7 ng/mL (n=5) after the low dose and 35.8+/-21.1, 26.0+/-7.7, 33.3+/-28.8, and 104.0+/-68.9 ng/mL, after the 1.5 mg dose. The highest oral fluid concentration of nicotine occurred at the longest infusion time at each dose. Oral fluid/plasma were >1 for up to 60 minutes after the low dose and 120 minutes after the high dose. There was no correlation between plasma and oral fluid nicotine concentrations.

Preparation and evaluation of release characteristics of 3TabGum, a novel chewing device

A new chewing gum device in the form of a three layers tablet (3TabGum) has been developed. The new drug delivery system is obtained, at room temperature, by direct compression using conventional pharmaceutical equipment. Basically, the resulting chewing gum tablets comprise a gum core combined with two protective antiadherent external layers, which prevent gum adhesion to the punches of the tableting machine. Drug release from a dosage form is the critical step in drug absorption and bioavailability, thus an experimental protocol has been designed to evaluate the efficiency of this kind of therapeutic system by verifying its capability to release the drug dose and by assessing the delivery rate. Simple diffusion into the medium causes the release of only a small percentage of the drug contained in the medicated chewing gum, while the delivery of the major part of the dose occurs during mastication. The results obtained in this study suggest that water soluble drugs are freely and easily released by chewing gums, while for actives characterized by reduced water solubility the release rate depends on the chewing time although all the drugs tested are completely released after a reasonable mastication time.

Release Kinetics of Catechins From Chewing Gum

Chewing gums containing catechins were prepared by applying a novel solid dispersion and hot-melt fluid bed coating method. The effect of varying levels of Eudragit coating to the granules on the prolonged release of catechins from chewing gum was investigated. In vivo release profiles of catechins from the formulations were investigated to determine its release kinetics. Dissolution data were used as the primary basis for comparison. The equations with zero order, first-order, or square root of time release kinetics were used to fit data. The results showed that the releases of catechins from chewing gum were well extended with the growing coating level of Eudragit to the granules. The statistical analysis using nonlinear regression software suggested that the Higuchi equation describes the data better than others. The relatively high degree of fit using the Higuchi equation implies that the kinetic process is involved in the release of drug from the dosage form. A possible release mechanism based on this profile is presented in this report. This approach suggested the potential of using chewing gum as a promising controlled-release delivery system of drugs. The effect of polyvinyl acetates with different crosslinkings on the release profiles of catechins was also studied.

Subjective effects of the nicotine lozenge: assessment of abuse liability

RATIONALE

A nicotine lozenge was developed as a novel smoking cessation aid. Abuse liability, which in this context refers to use by novices not addicted to tobacco, may be expected to be low for the lozenge due to the relatively slow route of nicotine absorption. However, its resemblance to commercially marketed lozenges and its palatability, intended to increase medication compliance, may increase its abuse liability, especially among younger individuals.

OBJECTIVES

The present study evaluated the abuse liability of the nicotine lozenge. Effects of the lozenge on cigarette craving were also measured.

METHODS

Subjective and physiological effects of the nicotine lozenge were tested in healthy adult smokers ( n=12, 22-55 years old); a group of younger subjects ( n=12, 18-21 years) was also included to allow for assessment of abuse liability of the lozenge in young adults specifically. Amphetamine and a confectionery lozenge were included in the study conditions as positive controls for abuse liability and palatability, respectively, and nicotine gum was included to allow for comparison with a marketed oral nicotine replacement product with low abuse liability.

RESULTS

The nicotine lozenge did not increase ratings of traditional abuse liability predictors (good effect, like effect, MBG scale of the ARCI), while amphetamine significantly increased ratings on these measures. The lozenge dose dependently decreased craving for cigarettes after 70 min of abstinence, but only in the older group. Palatability of the lozenge was rated lower than a confectionery lozenge, but not lower than nicotine mint gum.

CONCLUSIONS

Results suggest that the nicotine lozenge has low abuse liability, both in adults and young adults. The lozenge reduces craving to smoke, although craving reduction may not apply to young adults (18-21 years). Subjective effects of the lozenge are consistent with utility as a smoking cessation aid and are comparable to those of nicotine gum.

The effects of extrinsic context on nicotine discrimination

There is evidence from memory studies that context acquired in parallel with the encoded material will facilitate retrieval. However, relatively little is known of how context affects drug discrimination behaviour in humans. The present study employs conventional drug discrimination procedures to investigate the effects of music, as an external cue, on nicotine drug discrimination. Subjects were trained to discriminate a low dose of nicotine (1 mg) from placebo while listening to two different types of music [elated (EL) and depressant (DE): thought to induce happy and sad mood respectively]. Half of the subjects received EL music with nicotine and DE with placebo and the other half vice versa. At the end of training, subjects who reached the criterion (80% of trials identified correctly) entered the generalization phase and were required to discriminate different doses of nicotine (0, 0.25, 0.5 and 1 mg) by indicating how similar each sample was to the training dose. Generalization took place in the presence of either EL or DE music. Nicotine-appropriate responding during generalization was linearly related to dose, with subjects being able to distinguish 0.5mg of nicotine from placebo. Nicotine-appropriate responding at generalization was higher when the context (type of music) was the same as the one employed during discrimination training when nicotine was administered (i.e. a context-dependent generalization effect was present). In addition, it was shown that the context-dependent effect was due to the properties of the EL music. These data provide the first evidence that extrinsic context can facilitate nicotine discrimination in humans. In addition, the findings suggest that this facilitatory effect is not a general effect but is sensitive to specific attributes of the context.

Apparatus for studying in vitro drug release from medicated chewing gums

An apparatus for in vitro drug release testing of medicated chewing gums has been developed and is described in detail. The effects on the drug release when varying critical instrumental settings such as the chewing stroke frequency, the distance between the chewing surfaces, the twisting movements of these surfaces and the temperature of the test medium have been thoroughly investigated. It has been shown that the drug release can be tuned to obtain suitable drug release profiles for a number of products: Nicorette((R)) and Nicotinell((R)) (active substance nicotine), Travvell((R)) (dimenhydrinate), V6((R)) (xylitol) and an experimental formulation containing meclizine. The main usage of the present apparatus should be within quality control but the present study has also shown that it may be employed within development pharmaceutics since useful in vivo/in vitro relationships may be obtained due to the versatile settings of the critical instrumental parameters.

Caffeine antagonizes EEG effects of tobacco withdrawal

Six current cigarette smokers and coffee drinkers were given combinations of 0, 150, or 300 mg caffeine and 0, 2, or 4 mg nicotine polacrilex following 12-h nicotine and caffeine abstinence. On one study day, subjects were allowed to smoke cigarettes and to drink caffeinated beverages and no drugs were given. Tobacco and caffeine abstinence impaired performance on the serial addition/subtraction and digit recall tasks; decreased scores on the MBG scale and ratings of "clear-headed" and "quick-witted"; and increased ratings of "irritability," "muscular tension," "headache," "drowsy," "clumsy," "feeble," and "dreamy." The deprivation caused characteristic EEG signs of nicotine withdrawal including increased theta power and decreased alpha frequency. These EEG effects were reversed by cigarette smoking and caffeine administration, but nicotine polacrilex was less effective. Deprivation-induced performance and subjective measures were not changed by administration of nicotine and caffeine combinations.

Performance, subjective, and physiological effects of nicotine in non-smokers

Sixteen human volunteers with little or no experience using tobacco participated in one 4.5-h experimental session in which they were administered three doses of nicotine polacrilex gum (0, 2 and 4 mg) in ascending order at 90-min intervals. Physiological, subjective, and cognitive performance measures were assessed before and after each dose. Nicotine produced dose-related increases in heart rate and blood pressure and decreases in skin temperature. Nicotine also increased subjective ratings of dose strength and negative effects and decreased ratings of desire to repeat the same dose. There were dose-related trends toward decreased accuracy and increased response time on 3 of the 4 cognitive tests. These data do not support the hypothesis that nicotine enhances cognitive functioning in non-smokers.

Physiologic effects of nicotine polacrilex

Nicotine is the pharmacologically active agent in tobacco responsible for the maintenance of cigarette smoking behavior. Paradoxically, nicotine also offers the most promise in the successful treatment of cigarette smoking when it is delivered to the central nervous system in a safer and more manageable form. By transferring the physiologic dependence from nicotine contained in tobacco to nicotine bound in a polacrilex, the behavioral aspects associated with cigarette smoking can be removed with a minimal amount of discomfort or risk of relapse. Nicotine bound to a polacrilex and administered as a chewing gum is currently the replacement of choice since many of the systemic effects of nicotine delivered via this route are similar to the effects of nicotine delivered in cigarette smoke without the accompanying exposure to carbon monoxide and tar. Factors such as administered dose, schedule of dosing, and rate and vigor of chew, however, can significantly alter the desired effects. This paper provides a summary of the physiologic changes which may affect the effectiveness of nicotine gum as a pharmacologic adjunct in the treatment of tobacco dependence.