BIOADHESIVE BUCCAL DISCS OF FLUVASTATIN SODIUM

Fluvastatin sodium (FVS) is a cholesterol lowering agent (HMG-CoA reductase inhibitor) which undergoes extensive hepatic first pass metabolism causing an absolute bioavailability of ~30%. The aim of this work was to formulate a buccoadhesive disc of FVS to be applied to the buccal mucosa, releasing the drug in a unidirectional manner, in order to improve the bioavailability of the drug and lower the dose-dependent side effects. The bioadhesive discs were prepared by direct compression method using several polymers such as: guar gum, sodium alginate, sodium carboxymethyl cellulose, carbopol 934P, and hydroxypropylmethyl cellulose. Impermeable ethyl cellulose was applied as the backing layer. Different permeation enhancers such as bile salts, surfactants, fatty acids, chitosan, dimethyl sulfoxide, and polyethylene glycol 6000 (PEG 6000) were tested to improve the permeability of buccal mucosal membranes. The optimized formulation contained FVS, guar gum, PEG 6000, and sodium deoxycholate (permeation enhancer, 4%). It showed a drug release of 95.4% in 80 min, drug permeation through chicken pouch membrane (flux (J_ss) = 3.74 mg cm^-2 h^-1), ex vivo bioadhesion strength of 2.543 g, along with satisfactory bioadhesion time of 4.87 h. Physicochemical characteristics of the buccal discs such as drug content uniformity, disc thickness, disc hardness, surface pH, and swelling index were also evaluated.