Levosalbutamol Sulphate mucoadhesive buccal thin film formulation design and characterization: Effect of polyethylene glycol 400 as a plasticizer

Abstract

The present study aimed to design and evaluate mucoadhesive buccal thin films of levosalbutamol sulphate to circumvent pre-systemic elimination due to gastrointestinal degradation and hepatic first-pass metabolism. Films were prepared using four water-soluble polymers in varying proportions with PEG-400 as a plasticizer. A total of five formulations were developed and characterized for physicochemical parameters including surface pH, film thickness, folding endurance, mass and content uniformity, density, swelling index, disintegration time, percent moisture absorption/loss (PMA/PML), in vitro drug release kinetics, and ex vivo mucoadhesion time. All evaluations were performed in triplicate to ensure data reliability. The prepared films exhibited high folding endurance (>300), uniformity in mass and thickness, and a surface pH compatible with salivary fluid. Disintegration time and content uniformity met standard criteria. Drug release kinetics followed zero-order in two formulations, Higuchi model in two, and first-order in one. Mucoadhesion times ranged from 2 to 9 minutes, and the films demonstrated satisfactory stability under both dry and humid conditions.