Background: Buccal delivery of drugs can be used as an alternative administration route to
conventional oral route avoiding the liver first-pass effect and improving patient compliance.
Objective: The goal of this work was to develop dry emulsions for buccal delivery of ketoprofen, used
as a lipophilic model drug. The influence of two vegetable oils, olive oil or wheat germ oil, in the presence
of α-cyclodextrin and different drying techniques on the dry emulsion properties was evaluated.
Methods: Emulsions were prepared by adding olive oil or wheat germ oil to an aqueous solution of
α-cyclodextrin and subsequently dried through an oven, freeze-dryer or spray-dryer. Dry emulsions
were characterized in terms of yield, encapsulation efficiency, morphology and drug solid-state.
In vitro drug release and permeation studies were carried out to evaluate dry emulsion ability to release
the drug and to allow its permeation through the esophageal porcine epithelium.
Results: The formation of stable and milky emulsion was assured by cyclodextrin ability to interact
with oil components obtaining an inclusion complex with amphiphilic property able to act as a surfaceactive
agent. The drying process influenced the yield and the encapsulation efficiency, while no significant
differences were observed between olive oil and wheat germ oil. Freeze-dried emulsions, selected
as the best formulations, resulted in fast release of drug thereby ensuring its permeation across the epithelium.
Conclusion: Dry emulsions prepared with a simple and easy method, using natural ingredients and
avoiding synthetic surfactants and organic solvents, could be used for buccal delivery of lipophilic