Importance of the field: The buccal drug delivery system has been accepted as a potential non-invasive route of drug administration, with the advantages of avoidance of the first-pass metabolism, sustained therapeutic action and better patient compliance. However, transmucosal delivery of drugs by means of the buccal route is still very challenging. The main obstacles derive from the limited absorption area and from the barrier properties of the mucosa that have to be overcome for successful delivery drug molecules to the systemic circulation by this route.
Areas covered in this review: One long-standing approach for improving buccal drug delivery uses buccal absorption promoters, also called permeation enhancers. This requisite has fostered the study of permeation enhancers that will safely alter the permeability restrictions of the buccal mucosa. This review includes various classes of transmucosal chemical permeation enhancers and their mechanism of action. As enhancers influence drug delivery, further exploration of these compounds is required to understand their modifying action on the properties of buccal mucosa.
What the reader will gain: This review will help the readers in the selection of a suitable enhancer(s) for improving the buccal drug delivery for future endeavor.
Take home message: The authors imagine new buccal formulations bearing permeation enhancer(s) being commercialized in the coming years.