Background: Buccal drug delivery is a fascinating research field. Gel-based formulations present potent
characteristics as buccal systems since they have great physicochemical properties.
Methods: Among the various gels, in situ gels are viscous colloidal systems consisting of polymers; when physiological
conditions change (pH, temperature, ion activation), they are transformed into the gel phase. These
systems can improve bioavailability. Other systems, such as nanogels or emulgels can also be applied for buccal
delivery with promising results. Polymeric gel-based systems can be produced by natural, semisynthetic,
and synthetic polymers. Their main advantage is that the active molecules can be released in a sustained and
controllable manner. Several gels based on chitosan are produced for the entrapment of drugs demonstrating efficient
retention time and bioavailability due to chitosan mucoadhesion. Besides polysaccharides, poloxamers
and carbopol are also used in buccal gels due to their high swelling ability and reversed thermal gelation behavior.
Results: Herein, the authors focused on the current development of mucoadhesive gel systems used in buccal
drug delivery. After explaining buccal drug delivery and mucoadhesion, various studies with hydrogels, in situ
gels, and nanogels were analyzed as buccal gel systems. Various mucoadhesive gel studies with mucoadhesive
polymers have been studied and summarized. This review is presented as valuable guidance to scientists in formulating
buccal mucoadhesive drug delivery systems.
Conclusion: This review aimed to assist researchers working on buccal drug delivery by summarizing buccal
drug delivery, mucoadhesion, and buccal mucoadhesive gel systems recently found in the literature.