Tobacco Asia

50 tobaccoasia Issue 5, 2023 September / October By Thomas Schmid Early generation e-cigarettes and – later on – va- porizers were notoriously inefficient. That was largely due to technically unrefined heating coils and "wicks" (basically cotton wool soaked in a freebase nicotine solution). For that reason, vapes were often loaded with e-liquids containing nico- tine concentrations of up to 48 mg/ml or even higher to get a "hit" out of it; unimaginable today. Things could well have continued that way, but then the EU's Tobacco Products Directive (TPD) came along. It legislated that nicotine in e-liquids was to be limited to a maximum of 20 mg/ml, more or less forcing vape manufacturers to put their back into r&d to improve their devices' ef- ficiency. In addition, advances concerning better batteries and sophisticated digital interfaces that allowed users to tailor their personal vaping ex- perience were made. But these advances did not address the perhaps single most important key weakness of vaping at the time: the fact that many smokers who wanted to transition from tobacco to less harmful vaping did find the nicotine "rush" from vaping not as satisfying as what they were accustomed to from cigarettes. What is freebase nicotine? Freebase nicotine is the "natural" molecular form of nicotine, i.e. it has not "bonded" with another substance to form a chemical compound. As free- base nicotine has always been readily available, it consequently became the primary active ingredi- ent in e-liquids. Still used in many e-liquid brands today, it also is found in numerous other products, such as nicotine patches and pouches, lozenges, or gums. Extracted from tobacco leaves and purified, the substance easily dissolves in propylene glycol or vegetal glycerin to make e-liquids. However, besides freebase nicotine, tobacco leaves also con- tain a variety of nicotine salts, whereas the plants' pH level determines whether nicotine is primarily present in it as freebase nicotine or as a salt. "In some cases, nicotine exists in the form of salt [in the plant], while in other cases it is pres- ent as the basic molecule," explained Tom Xie, se- nior director of the SMOORE Research Center in Shenzhen, China. "Generally speaking, the higher the pH value [i.e. alkaline] in the tobacco plant, the higher the amount of nicotine in its pure form; and the lower the pH [i.e. acidic], the lower the amount of nicotine in its salt form," he said. New possibilities with nicotine salts Defined in chemical terms, a "salt" is a compound consisting of an ionic assembly of positively charged cations and negatively charged anions, re- sulting in no net electric charge. In that respect, a nicotine salt can either form naturally in the to- bacco leaf itself or – more commonly nowadays – it is chemically synthesized by suppliers such as Alchem, for example. But from whichever source they may come, nicotine salts offer amazing new possibilities for driving vaping industry innova- tion. Why is that so? What makes e-liquids con- taining one or another nicotine salt so different from e-liquids produced with freebase nicotine? Well, it all comes back to the already mentioned key weakness of early e-liquids. "When a nicotine salt is used in an e-liquid in- stead of freebase nicotine, it will greatly improve Nicotine Salts Vs. Freebase Nicotine Nicotine salts are regarded a much better choice to be used in e-liquids than freebase nicotine. Two experts fill us in on the reasons why. Devices within SMOORE's vape brand FEELM are routinely loaded with nicotine salt e-liquids. Pictured here is the disposable FEELM Max vape pen. Credit: SMOORE

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