Microemulsions are thermodynamically stable, isotropic drug delivery systems composed of oil, water, surfactant, and co-surfactant, offering improved solubility and bioavailability of poorly water-soluble drugs. The present study aimed to develop and evaluate a mucoadhesive microemulsion system of Marich (Piper nigrum Linn.) containing piperine for enhanced drug delivery through the nasal route. The formulation was prepared using Capmul MCM as oil, Labrasol and Transcutol as surfactant and co-surfactant, along with mucoadhesive polymers. The prepared formulations were evaluated for clarity, thermodynamic stability, dispersibility, transmittance, viscosity, pH, drug content, in vitro drug release, and ex vivo drug permeation. The optimized microemulsion showed a transparent, stable, and less viscous system with suitable nasal pH (5.56), high drug content (98.73 ± 0.75%), and improved drug release compared to Marich churna and drug solution. The formulation demonstrated enhanced ex vivo permeation (86.36 ± 4.20%) due to improved solubilization and nanosized lipidic drug incorporation. The developed piperine microemulsion remained stable under accelerated stability conditions and showed potential as a promising brain-targeted delivery system for piperine in neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease.

Keywords: Piperine, Piper nigrum, Microemulsion, Mucoadhesive drug delivery, Brain targeting.