DEVELOPMENT AND IN-VITRO CHARACTERIZATION OF NANOEMULSION-BASED BUCCAL PATCHES OF VALSARTAN

The aim of the study was to develop and characterize mucoadhesive buccal patches of valsartan (VAL) in nanoemulsion (NE) form and to evaluate the impact of this formulation in improving its solubility, mucoadhesive strength and in-vitro permeation in comparison to the traditional mucoadhesive VAL patches. A thermodynamic stable VAL-loaded NE was constructed and evaluated by centrifugation, heating/cooling cycles, and freeze/thaw cycles. It had a mean droplet size of 22.5 nm and composed of 40% w/w water, 10% w/w oleic acid: Labrasol® at a ratio of 2:1 v/v, 50% w/w polysorbate 20: Transcutol®-P at a ratio of 1:3 v/v and. Bi-layered patches were prepared using 3% w/v ethylene vinyl acetate in dichloromethane as backing layer and 1.5% w/v Carbopol® 971P aqueous solution with VAL-loaded NE as mucoadhesive layer . Patches showed acceptable weight variation, thickness, drug loading, folding endurance, mucoadhesive strength and in-vitro permeation. NE-based patches were more effective in enhancing the penetration of VAL than traditional patches, without significant difference in the mucoadhesive strength. They showed higher steady state flux and permeability coefficient than the traditional patches with a flux enhancement ratio of 2.36. The study concluded that reducing the particle size to the nano-scale appears to be a promising approach to obtain VAL products with higher drug permeability that can be tailored to optimize drug release profile in-vivo.