Development And Characterization Of Nano-Ethosomal Patch Of Metformin For Enhanced Dermal Penetration

Abstract

The present investigation aimed to develop and characterize a nano-ethosomal transdermal patch of metformin hydrochloride for enhancing dermal penetration and controlled drug delivery. Metformin, a first-line antidiabetic agent, suffers from poor oral bioavailability due to gastrointestinal degradation and extensive hepatic metabolism, necessitating frequent dosing. To overcome these drawbacks, nano-ethosomes—phospholipid-based soft vesicles enriched with ethanol—were prepared using thin-film hydration technique and optimized for particle size, entrapment efficiency, and zeta potential. The optimized ethosomal vesicles exhibited nanometric size distribution (<200 nm) with high drug encapsulation and good stability. These vesicles were further incorporated into a transdermal patch formulated using hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) as film-forming polymers with glycerol as a plasticizer. The prepared patches were evaluated for thickness, tensile strength, drug content uniformity, folding endurance, and surface morphology. In vitro skin permeation studies using Franz diffusion cell on excised rat skin demonstrated significantly enhanced permeation compared to conventional patches or drug solution, confirming the penetration-enhancing role of ethosomes. The release profile followed a controlled, sustained pattern suitable for prolonged therapeutic action. Overall, the developed nano-ethosomal patch offers a promising alternative platform for metformin transdermal delivery, enhancing bioavailability and potentially improving patient compliance in diabetes management.