Novel bioadhesive delivery system for percutaneous local anaesthesia.

We have assessed the efficacy of a novel bioadhesive amethocaine patch device, compared to Ametop gel, in a randomized, double-blinded trial. Patch and gel formulations, including placebos, were applied to the forearms of volunteers (n = 30) for 40 min. Once the formulations were removed from the skin, anaesthesia was assessed by volunteers using a conventional pinprick test. Pain scores were recorded for 4 h after removal of gels and patches. Statistical analysis of the results indicated that both amethocaine gel and patch preparations were superior to placebo (P < 0.05). No significant difference was observed between amethocaine gel and patch formulations (P > 0.05) in either onset time or duration of action for percutaneous local anaesthesia. The results of this study indicate therefore that the novel bioadhesive patch provides clinically comparable anaesthesia to the established gel formulation in a more defined dosage form.