Physical methods to promote drug delivery on mucosal tissues of the oral cavity.

INTRODUCTION: The success of drug delivery through the mucosal tissue of the oral cavity represents a current challenge as well as a great future perspective. The need for more rapid onset of action and improved absorption of medications has resulted in great development of drug delivery technologies that use physical methods to overcome the barrier properties of oral mucosae. AREAS COVERED: This review discusses the various physical techniques which have been, and are being, explored to sustain drug delivery in the oral cavity. In particular, supersaturation, eutectic formation, iontophoresis, electroporation, sonophoresis, laser radiation, photomechanical waves and needleless injection are considered. Following a careful selection of the most appropriate site and technique, in agreement with local variations of the oral mucosal permeability features, physical methods to promote drug delivery can improve treatment of diseases. EXPERT OPINION: Although physical methods are very promising to promote drug delivery through keratinized epithelial tissues, they are not extensively used on the oral cavity mucosae. The authors feel that, in the near future, these methods could be further developed to provide noninvasive and convenient means for locoregional/systemic delivery of drugs with poor bioavailability profile, short half-life and multiple doses scheduling. This review will help the readers in the selection of a suitable physical method for improving drug delivery in the oral cavity for future chances. The authors imagine that new formulations or devices will be marketed in the coming years.