Preface for buccal drug delivery theme issue

During the past years, buccal drug delivery has attracted the attention of researchers looking for alternative delivery routes of administration. As an alternative to oral drug delivery, the buccal mucosal route avoids the passage through the acidic gastric environment, intestinal and bacterial enzymatic activity, absorption issues associated with the intestinal epithelium (e.g. P-glycoprotein efflux), and the first pass metabolism of the liver. Therefore, the buccal route could be a good delivery route for macromolecules and other drugs not compatible with the gastrointestinal tract environment. This "Buccal Drug Delivery" special edition of Drug Development and Industrial Pharmacy aims to bring together a range of different aspects relevant to the growing field of buccal drug delivery. The special edition includes thorough reviews of the literature, as well as original research articles touching on most prominent features related to buccal drug delivery systems, such as the move toward the use of nanotechnology in different ways to facilitate buccal drug delivery with the potential to prompt future product developments.