A contained nicotine solution comprising: a container； and a nicotine solution contained within the container, wherein at least 5 wt% of the nicotine present in the solution is in protonated form； and wherein at least a portion of the container in contact with the nicotine solution is formed from polycarbonate or polypropylene. Preferably the nicotine is protonated by benzoic acid, levulinic acid and mixtures thereof. Also claimed is the contained nicotine solution as part of an electronic vapour provision system (e-cigarette) and a process of stabilising a nicotine solution by protonating the nicotine present in the solution such that at least 5 wt% of the nicotine is in a protonated form.
