Solubilization of fluocinolone acetonide by cosolvents and surfactants for buccal solution preparation

Abstract

Objective: Fluocinolone acetonide (FA) buccal solution was prepared for treatment of oral lichen planus using cosolvents and surfactants to enhance FA solubility. Results: Based on solubility power (σ) in the concentration range of 0–40% w/w, cosolvents enhanced FA solubility in the order; polyethylene glycol 400 (σ = 3.06 × 10−2)> propylene glycol (σ = 2.92 × 10−2)> glycerin (σ = 0.95 × 10−2). The order of FA solubility in surfactant solutions was 1% polysorbate 80 (1.04 × 10−2 %w/v)>0.05% cetylpyridinium chloride (0.69 × 10−2 %w/v)>0.1% sodium lauryl sulfate (SLS) (0.27 × 10−2 %w/v). Cosolvents increased the critical micelle concentration, especially for ionizable surfactants (SLS and cetylpyridinium chloride [CPC]). These effects of cosolvents on micellization impeded the ability of the surfactants to increase FA solubility. Both polysorbate 80 and CPC induced degradation of FA. Conclusion: We conclude that a 0.01% FA buccal solution should be prepared in a cosolvent system without use of surfactants.