Alveolar deposition and heat-not-burn products
It is now becoming clear that there are significant differences in the way nicotine gets into the blood and arrives at the brain. This impacts the speed of delivery, the time lag between the puff and the buzz. Burning tobacco, with its carcinogenic tars, does it faster, and delivers a higher nicotine concentration, for a bigger buzz. This is also why burning tobacco is more addictive than other nicotine delivery systems. The mechanism in question is called “alveolar deposition”, and it means that the nicotine punch is expedited in the lungs' alveoli, the tiny cells that are the interface between the body's breathing system and its blood circulation.
Scientists for Big Tobacco, it appears, have known about alveolar deposition for some time, and according to some nicotine specialists, have worked hard to enhance it, as a way of making cigarettes more addictive.
The vapor from a vaping system does not deliver nicotine as rapidly, or as abundantly, so vapers don't get as much nicotine as smokers do. All three American Big Tobacco companies have at least doubled the nicotine concentrations in their e-cig liquids, while NJOY has tried to enhance delivery with a pharmaceutical agent, according to the New York Times.
For many vapers the lower efficiency of an e-cig at nicotine delivery is a plus. After all, there are many people who make a conscious effort to reduce the nicotine concentrations of their e-liquids. These are vapers who are hoping to get off nicotine altogether in the long run, either by continuing to vape zero-nicotine liquids, or by giving up vaping itself after using it to quit smoking. Chances are these are people who respond more to the behavioral aspects of cigarette addiction, rather than the chemical ones. They value a cigarette or a vape as a ritual to mark the end a meal or a sexual encounter, to delimit a coffee break, or to cement a friendship or a deal. The fact that it gives a chemical buzz is partially or wholly coincidental to them.
But some smokers need the chemical side of the smoking experience. Their addiction is more chemical than behavioral. Recent studies have shown that personal differences in metabolic rate have an impact on the ease or difficulty of a smoking cessation effort. And it is clear that scientists for Big Tobacco are busily searching for ways to get alveolar deposition into the e-cig experience.
The New York Times reported on Christmas Day (“ho ho ho”) that Phillip Morris International, in its labs in Neuchatel, Switzerland, is earnestly studying the matter. PMI has been telling us for some time now that it is making a product containing actual tobacco that will produce a nicotine buzz by heating said tobacco but not burning it. (When they weren't busy, that is, practicing their skullduggery on sleazy lobbying efforts against the TPD, efforts that gave the vaping community a bad name.) The Times reports that Neuchatel is the epicenter of their efforts, and the facility has banks of machines puffing away at such devices, with sensors to measure speed and strength of nicotine delivery. The “heat-not-burn” devices, called iQOS, have been tested in Poland, and are currently being test-marketed in Japan. Presumably PMI hopes that such products will achieve something approximating the strength and speed of alveolar deposition without delivering tars (or without appearing to do so). Preliminary studies do show some improvement.
RJ Reynolds is dragging out its heat-not-burn product Eclipse (which flopped in the 90s), rebranded as Revo.
What does this mean to the vaper on the street (at appropriate distances from school entrances, of course)? Not much, unless you are one of the unlucky ones whose nicotine dependency is more chemical in nature. Still, it is good to be sensitized to such differences, to enable more effective cessation planning.
In a larger sense, it underlines the divide between opposing motivations for vaping advocacy. Big Tobacco clearly wants to use vaping as a way of keeping smoking alive, while independent vaping concerns strive to end it.