Types and evaluation of in vitro penetration models for buccal mucosal delivery

Oral buccal mucosal delivery has the advantage of avoiding gastrointestinal drug degradation, reducing hepatic firstpass effects, and improving patient compliance. In recent years, it is becoming a drug delivery route that researchers have paid attention to. One of the major constraints to bringing buccal mucosal preparations to market today is that the mucosal permeability of the preparations cannot be accurately evaluated. In vitro permeation experiments are essential and are a valuable assisting method for in vivo transbuccal mucosal absorption studies. In vitro permeability evaluation can assess the permeability of the drug and the possibility of transbuccal mucosal delivery. One of the most important factors affecting the results of in vitro permeability studies are the proper selection and use of permeability models and diffusion cells. This article analyzed the characteristics of various in vitro penetration models of buccal mucosal delivery and the main factors affecting its application, listed methods for evaluating mucosal integrity and viability, and summarized the characteristics and applicability of commonly used diffusion cells. The purpose of this article was to provide a reference for the rational selection of in vitro permeation models and the use of diffusion cells in new drug research.