An investigation of the chick chorioallantoic membrane as an alternative model to various biological tissues for permeation studies

Objectives The chick chorioallantoic membrane (CAM) was explored as a biological membrane for use in the study of drug permeation with a Franz diffusion cell. Methods The CAM was removed from fertilized chicken eggs of embryo age 9–18 days. The permeation profiles of nicotine through the fresh CAM were first obtained with a Franz diffusion cell. The permeation profiles of nicotine through frozen CAM, snake skin, pig skin, pig retina and pig buccal mucosa were also determined and compared with those of the fresh CAM. Key findings The permeability coefficient of the CAM varied with its age. The CAM at embryo age 13 was the most robust, showing the lowest standard error in permeability. It was thus chosen for comparative studies with snake skin, pig skin, retina and buccal mucosa. The CAM was found to be most similar to the buccal mucosa in terms of permeation profile and permeability coefficient values. Frozen CAM was also found to have a higher permeability coefficient than fresh CAM. The enhanced permeability was attributed to freezing, which affected the integrity of the CAM structure. Conclusions From the findings, CAM shows potential as an alternative to the pig buccal mucosa as an in‐vitro buccal model. The robustness of the CAM for drug permeation studies is affected by its age.