Oral PowderJect: a novel system for administering local anaesthetic to the oral mucosa

Objective To assess the feasibility of using an Oral PowderJect (OPJ) to safely deliver a dose of dry powdered anaesthetic to the oral mucosa, producing an analgesic effect. Design Single centre: Part 1. An open, non-randomised safety study to check for mucosal damage; Part 2. A double blind sham controlled study to test the anaesthetic effect. Setting General practice. Subjects Adult, healthy volunteers (4 male, 10 female). Materials and methods Part 1. An OPJ was used to deliver powdered lidocaine hydrochloride to the mucosal surface which was then checked visually for damage. Part 2. An OPJ containing lidocaine hydrochloride (active) or an empty OPJ (sham) was fired at the oral mucosa. The treated area and an untreated (control) site were probed with the back end of a dental needle. Results The OPJ delivery caused no visible mucosal damage. The median VAS score for pain on blunt probing was 10 for the OPJ active sites. This was significantly lower than the median VAS score for the sham sites at 30 (P = 0.0033) and the control sites at 58 (P< 0.0001). Conclusions The OPJ can safely deliver powdered lidocaine hydrochloride to the oral mucosa without causing tissue damage. The OPJ delivery of powdered lidocaine hydrochloride can significantly reduce the pain from a blunt needle probe at 1 minute post delivery.