6‐Methylnicotine: a new nicotine alternative identified in e‐cigarette liquids sold in Australia

• DOI: 10.5694/mja2.52423
• Publication Date: 2024-08-27T07:28:20Z
• Authors: Caitlin Jenkins; Celine Kelso; Jody Morgan
• Keywords: Electronic cigarette; Ingredient; Tobacco product; Packaging and labeling

In Australia, electronic cigarette (e-cigarette) use has nearly tripled since 2019, despite legal restrictions.1 These vaping products generally contain the carrier fluids propylene glycol and glycerine, flavouring chemicals, cooling agents, nicotine.2 Most users purchase their outside intended sources,3, 4 in what federal government describes as a "black market".5 At time of study reported this article, prescription was required for purchasing nicotine-containing e-cigarette Australia.6 To enable over-the-counter sales prevent seizure during customs controls, some suppliers have modified packaging.2 We investigated new advertised Australia containing nicotine alternative (Box 1) that manufacturers claim passes routine testing (ie, no detected), facilitating sale to Australian adults without prescription. purchased from three November 2023: four concentrated solutions dilution before five ready-to-use products. All samples were analysed using gas chromatography–mass spectrometry methods described our earlier publication2 (Supporting Information). The purified fully characterised by nuclear magnetic resonance spectroscopy high resolution mass spectrometry. did not seek formal ethics approval analysis. nine contained an ingredient would be identified standard analytical nicotine; complementary chemical characterisation techniques Information) it 6-methylnicotine 2, Box 3). Only one other product (one United States brand), but complete confirm its structure.7 vitro affinity nicotinic cholinergic receptors is higher than nicotine, psychotropic potency times greater.8 cytotoxicity exceeds at similar concentrations, lower dosage been recommended products.9 difference toxicity between particularly concerning given concentration we assessed. Samples ALT-01 ALT-02, each labelled "100 mg/mL [nicotine] equivalent", respectively about one-third one-fifth equivalent listed concentration, whereas ALT-03 ALT-04, "10%" solutions, much 100 2). While instructions on retailers' websites concentrations indicated or packaging. differences labelling actual these could confuse users, increasing risk accidental exposure compound with unknown health effects. Ready-to-use (ALT-05 ALT-09) order magnitude content currently available products2 Benzoic acid, included reduce throat irritation converting benzoate,10 detected seven samples. Whether conversion benzoate salt same effect unknown. One limitation small number analysed. undertook thorough internet search identify, purchase, analyse all including alternatives, compounds may also used alternatives. found "nicotine alternative"-containing sold 6-methylnicotine. range determined limited information potential effects are both concerning. toxicology consequences inhaling should investigated, long term Clinicians aware availability Recent changes regulation banned any prescription, closing loophole legally distribute products.4, 5 However, further novel developed circumvent regulations. This project funded (purchase analysis samples) University Wollongong, Faculty Science, Medicine Health Small Grant Scheme. Open access publishing facilitated part Wiley – Wollongong agreement via Council Librarians. No relevant disclosures. data underlying request contacting corresponding author. * Brand names redacted. SD = deviation. For replicate measurements. † Presence benzoic acid indicates present salt; absence suggests base. Supplementary Please note: publisher responsible functionality supporting supplied authors. Any queries (other missing content) directed author article.