In vitro evaluation of mucoadhesive films for gingival administration of lidocaine.

The aim of this study was the optimization of a lidocaine-based film formulation for the prevention of pain from needle prick during the injection of local anesthetic in dentistry. Film performances were evaluated in vitro by studying lidocaine permeation across pig esophageal epithelium as model for nonkeratinized buccal mucosa. The results obtained showed that the molecular weight of the film-forming polymer had no effect on lidocaine transport. The introduction of the adhesive Plastoid® into the film determined a significant increase of drug permeation rate, which was further improved by the addition of Azone®. On the contrary, the effect of sodium taurocholate was negligible.