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 nano-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 developed with a mean droplet size of 22.5 nm. It was composed of 40% w/w water, 10% w/w oleic acid : Labrasol (R) at a ratio of 2 : 1 v/v, and 50% w/w polysorbate 20 : Transcutol (R)-P at a ratio of 1 : 3 v/v. Bi-layered patches were prepared using 3% w/v ethylene vinyl acetate in dichloromethane as the backing layer and 1.5% w/v Carbopol (R) 971P aqueous solution mixed with VAL-loaded NE as the mucoadhesive layer. Patches showed acceptable weight variation, thickness, 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 a higher steady-state flux and permeability coefficient than the traditional patches with a flux enhancement ratio of 2.36. The study concluded that NE-based patch is a promising approach that can be tailored to optimize drug release profile in-vivo.