Regulatory toxicology and pharmacology : RTP
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Regul. Toxicol. Pharmacol. · Nov 2008
Randomized Controlled Trial Comparative Study12-week clinical exposure evaluation of a third-generation electrically heated cigarette smoking system (EHCSS) in adult smokers.
This randomized, controlled, forced-switching, open-label, parallel-group, single-center study in 90 male and female adult smokers evaluated six biomarkers of tobacco smoke exposure over a 12-week period of unrestricted smoking in the participants' normal life setting. Baseline biomarker levels were measured, then participants were randomly assigned to switch to an electrically heated cigarette smoking system (EHCSS, Series K) or to continue smoking a conventional cigarette (CC) of similar tar yield (Federal Trade Commission method) for 12 weeks. Compared to Baseline, adult smokers who switched to the EHCSS for 12 weeks in their normal life setting had significantly reduced nicotine equivalents (-33%), total NNAL (a biomarker for NNK, -63%), 1-OHP (a surrogate biomarker for polycyclic aromatic hydrocarbons, -38%), carboxyhemoglobin (a biomarker for carbon monoxide, -23%), 3-HPMA (a biomarker for acrolein, -25%) and S-PMA (a biomarker for benzene, -49%), whereas exposure was stable in the CC control group.
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Regul. Toxicol. Pharmacol. · Nov 2008
Randomized Controlled Trial Comparative StudyEnvironmental tobacco smoke (ETS) evaluation of a third-generation electrically heated cigarette smoking system (EHCSS).
This sub-study of a randomized, controlled, forced-switching, open-label, parallel-group, clinical study compared environmental tobacco smoke (ETS) produced when 60 male and female adult smokers switched to a third-generation electrically heated cigarette smoking system (EHCSS), continued to smoke a conventional cigarette (CC), or stopped smoking (No-smoking). Concentrations of air constituents including respirable suspended particulate (RSP), carbon monoxide (CO), ammonia and total volatile organic compounds (TVOCs) and ETS markers including solanesol-related particulate matter (Sol-PM), ultraviolet absorbing particulate matter (UVPM), fluorescent particulate matter (FPM), nicotine and 3-ethenyl pyridine (3-EP) were measured in a ventilated, furnished conference room over a 2-h period on separate occasions for each smoking condition. ⋯ Concentrations of ammonia were reduced by 41% and concentrations of other selected constituents of ETS were reduced by 87-99% in the air of a room in which EHCSS cigarettes were smoked as compared to concentrations in the same room when conventional cigarettes were smoked. Switching from conventional cigarette smoking to the EHCSS resulted in substantial reductions in concentrations of several markers of environmental tobacco smoke.
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Regul. Toxicol. Pharmacol. · Nov 2008
Randomized Controlled TrialShort-term clinical exposure evaluation of a third-generation electrically heated cigarette smoking system (EHCSS) in adult smokers.
This randomized, controlled, forced-switching, open-label, parallel-group, single-center study in 100 male and female adult smokers evaluated 12 biomarkers of tobacco smoke exposure. We measured exposure to the following smoke constituents: nicotine, pyrene, tobacco-specific nitrosamines, three aromatic amines, carbon monoxide, benzene, acrolein, crotonaldehyde, and 1,3-butadiene. ⋯ After adjusting for the residual effect (carryover effects due to long elimination half-life and non-tobacco confounding sources of exposure), the mean percent decrease from Baseline for all 12 biomarkers ranged from 47% to 90%. In conclusion, switching for 8 days from a conventional cigarette to the EHCSS substantially reduced exposure of adult smokers to several constituents of both the particulate and gas phases of cigarette smoke.
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Regul. Toxicol. Pharmacol. · Nov 2008
Comparative StudySmoke chemistry, in vitro and in vivo toxicology evaluations of the electrically heated cigarette smoking system series K.
The Electrically Heated Cigarette Smoking System Series K (EHCSS) produces smoke through the controlled electrical heating of tobacco. Evaluation of the EHCSS was accomplished by comparison with commercial and reference cigarettes, using International Organization for Standardization (ISO) and alternative puffing regimens based on nicotine exposures measured in a short-term clinical study. Using the alternative puffing regimen and compared with conventional cigarettes on a per cigarette basis, the EHCSS had 50-60% reductions in tar and nicotine; at least 90% reductions in carbon monoxide, nitrogen oxides, 1,3-butadiene, isoprene, acrylonitrile, polyaromatic hydrocarbons, hydrogen cyanide, aromatic amines, tobacco specific nitrosamines, and phenol; and least a 40% reduction in 2-nitropropane. ⋯ In vivo testing under ISO smoking conditions in the mouse skin painting assay demonstrated later dermal tumor onset, lower dermal tumor incidence, reduced dermal tumor multiplicity, and a lower proportion of malignant dermal tumors in EHCSS smoke condensate-exposed mice. Thirty-five day and 90-day nose-only inhalation studies in rats showed reductions in pulmonary inflammation and other biological activity, including histopathological endpoints. We conclude that under the conditions of these in vitro and in vivo studies, the EHCSS demonstrated significantly lower biological activity compared to conventional cigarettes, and may suggest the potential for reductions in human smokers.