Development and biopharmaceutical evaluation of aqueous micelle based corticosteroid formulations for topical treatment of oral lichen planus

The dearth of approved products to treat oral lichen planus (OLP) compels off-label use of dermatological corticosteroid formulations not optimized for indications in the oral cavity. The aims of this study were to develop aqueous micelle based formulations of triamcinolone acetonide (TA) and fluocinonide (FLU), using D-tocopheryl polyethylene glycol succinate, and to investigate corticosteroid delivery to the epithelium-lamina propria junction region - the anatomical target for OLP treatment - in comparison to that from marketed products. Total mucosal deposition of TA after application of Kenacort® A Orabase® (0.1 % TA) and micellar hydrogel (0.1 %) was 242.1 ± 68.5 and 5936.7 ± 1269.6 ng/cm², respectively. For FLU, deposition after application of Novoter (0.05 % FLU) and micellar hydrogel (0.05 %) was 617.1 ± 126.5 and 2580.0 ± 285.5 ng/cm², respectively. A buccal biodistribution study showed that application of micelle hydrogels under occlusion for 30 min delivered 117.0 ± 15.6 ng/cm² and 225.6 ± 36.7 ng/cm², of TA and FLU, respectively, to the epithelium-lamina propria junction region. In contrast, the amounts deposited after applying Kenacort® A Orabase® and Novoter, were < LOQ. The results demonstrated that TPGS-based micelles improved mucosal bioavailability of TA and FLU in the epithelium-lamina propria junction region and might serve to improve topical OLP therapy.