In vitro permeation through porcine buccal mucosa of Salvia desoleana Atzei & Picci essential oil from topical formulations

In the light of recent studies, which have shown that the essential oil derived from some Lamiaceae species has appreciable anti-inflammatory activity, moderate anti-microbial action and the ability to inhibit induced hyperalgesia, an assessment of the diffusion and permeation of Salvia desoleana Atzei and Picci (S. desoleana) essential oil through porcine buccal mucosa was considered useful for a possible application in the stomatological field. Topical formulations (microemulsions, hydrogels and microemulsion- hydrogels) were prepared for application to the buccal mucosa. The mucosa permeation of the oil from the formulations was evaluated using Franz cells, with porcine buccal mucosa as septum between the formulations (donor compartment) and the receptor phase chambers. The study also aimed at optimising the permeability of the S. desoleana essential oil by means of an enhancer, the diethylene glycol monoethyl ether Transcutol®. The diffusion of the oil through the membrane was determined by evaluating the amount of essential oil components present in the receiving solution, the flux and the permeation coefficient (at the steady state) in the different formulations at set intervals. Qualitative and quantitative determinations were done by gas chromatographic analysis. All the formulations allow a high permeability coefficient in comparison with the pure essential oil. In particular, the components with a terpenic structure (β-pinene, cineole, α-terpineol and linalool) have the highest capacity to pass through the porcine buccal mucosa when compared to the other components (linalyl acetate and α-terpinil acetate). Moreover, the enhancer, diethylene glycol monoethyl ether largely increases the permeation of the essential oil components in relation to the concentration. (C) 2000 Elsevier Science B.V.