Ionic conjugates of lidocaine and sweeteners as better tasting local anesthetics for dentistryElectronic supplementary information (ESI) available: 1H, 13C and HRMS data for all the synthesized products 3a-3c. See DOI: 10.1039/c5tb00674k

Lidocaine is the most widely utilized intraoral injected dental anesthetic, used for more than 500 million dental injections per year. Local anesthesia is essential for pain-free dentistry, yet intraoral injections are often considered painful and a source of anxiety for many patients. Any new anesthetics that will reduce the stress and anxiety of dental injection are expected to be beneficial. A novel chemical approach to taste modulation is proposed, in which the lidocaine cation is coupled with anionic sweeteners such as saccarinate and acesulfamate. The ionic conjugates synthesized using anion exchange techniques, were much less bitter, demonstrated a high local anesthetic potential in animal studies, and were as safe as the original hydrochloride. Based on the currently robust market for lidocaine it is expected that the resulting anesthetics will be in high demand in clinical practices worldwide. Ionic conjugation of lidocaine with artificial sweeteners creates a new type of taste modulated materials for dentistry.