Nicotine formulation plays a decisive role in how vaping and oral nicotine products perform, how they feel to the user and how they are assessed by regulators. The growing use of nicotine salts, rather than freebase nicotine, reflects a shift toward formulations that deliver nicotine more efficiently while addressing issues of harshness, stability and user acceptability. Here, Paul Hardman, managing consultant at nicotine testing and regulatory consultancy Broughton, explains why nicotine salts have become central to modern product development.
In vaping products, nicotine salts are primarily used to moderate the irritation associated with freebase nicotine. Protonating nicotine reduces its volatility, which limits nicotine loss from aerosol droplets before inhalation. This alters where absorption takes place, with less uptake in the mouth and upper airways and greater absorption in the lungs. Delivery at the alveoli, where surface area is high and blood is well oxygenated, supports faster systemic uptake and more rapid onset of effect.
This mechanism allows nicotine salt vapour products to achieve pharmacokinetic profiles that are closer to those of combustible cigarettes than formulations based on freebase nicotine. While overall exposure still depends on factors such as nicotine concentration and device aerosol output, the resulting delivery profile can feel more familiar to adult smokers seeking alternatives to smoking.
In oral nicotine pouches, the formulation challenge is different. Freebase nicotine can cause irritation when held against oral tissue, an effect that salts may reduce. At the same time, protonated nicotine crosses biological membranes less readily. This creates scope for formulators to control release characteristics through buffering systems and other formulation strategies, balancing comfort with effective nicotine delivery.
Nicotine salts also introduce formulation and testing considerations. Lower pH values can increase the likelihood of interaction between e-liquids and device components, particularly metals. Under certain conditions, metal ions may leach into the product, with implications for flavour, stability and safety. Excessively acidic formulations may also irritate mucous membranes.
Acid selection therefore matters. Different salts vary in thermal stability and degradation behaviour, while some acids can influence flavour profiles. These factors shape stability study design, impurity profiling and analytical method development.
Formulation decisions can also affect regulatory classification in some jurisdictions, influencing whether products fall under consumer or medicinal frameworks. Understanding how nicotine salts interact with devices, formulations and regulatory expectations is essential for developing products that perform consistently and withstand scrutiny throughout their lifecycle.
Working with a trusted compliance partner can provide valuable support throughout product development, helping teams navigate the practical and regulatory implications of nicotine salt formulation. This can include selection and validation of appropriate salt systems, development and validation of analytical methods, and the design of stability and impurity studies aligned with regulatory expectations.
This ensures the product has the requisite support for PMTA, MAA, TRPR, and consumer product pathways, ensuring robust data and informed decisions are made at every stage, with the relevant information included in your submission files. To find out more about nicotine salts and formulation approaches in nicotine products, visit Broughton’s website.
