Permeability of triamcinolone acetonide, released from mucoadhesive films, through a buccal mucosa-mimetic barrier: Permeapad™

Objectives

The permeability of triamcinolone acetonide (TA), from bilayer mucoadhesive buccal films, through a biomimetic membrane, Permeapad™, was investigated employing Franz diffusion cell. The delivery systems composition and ethyl cellulose (EC) backing layer, on drug permeability, were assessed.

Methods

Three TA-loaded films were tested; hydroxypropyl methylcellulose (HPMC K4M; bilayer [F1] and monolayer), HPMC K4M/Polyvinylpyrrolidone (PVP): 90/10 [F2], and HPMC K15M film [F3]. All films contained propylene glycol (PG-plasticiser). TA solution alone was used as a control. TA permeability via a Permeapad™ barrier, simulating buccal mucosa, was assessed over 8 h using a Franz diffusion cell. TA permeated into the receptor compartment, released in the donor compartment, and located on/within the Permeapad™ barrier were analysed using UV-spectrophotometer.

Results

45.7 % drug retention within the Permeapad™ barrier was delivered from F1 (highest). F1, F2, and F3 significantly improved the TA’s permeability through Permeapad™, compared to TA solution alone (e.g., 8.5 % TA-solution, 21.5 %-F1), attributed to the synergy effect of HPMC and propylene glycol acting as penetration enhancers. F1 displayed a significant increase in drug permeability (receptor compartment; 21.5 %) compared to F3 (17.0 %). PVP significantly enhanced drug permeability (27.5 %). Impermeable EC backing layer controlled unidirectional drug release and reduced drug loss into the donor compartment (e.g., ∼28 % for monolayer film to ∼10 % for bilayer film, F1).

Significance

The mucoadhesive films demonstrated improved TA permeability via Permeapad™. The findings suggest that these bilayer mucoadhesive films, particularly F1, hold promise for the effective topical treatment of oral mucosa disorders, such as recurrent aphthous stomatitis and oral lichen planus.