Fabrication and Characterization of Piroxicam-Loaded Glycolated Chitosan-Stabilized Transdermal Patch

Objective: The transdermal drug delivery system is designed to transport drugs into the bloodstream through the skin. Methods: A controlled-release transdermal patch of piroxicam was developed using glycol chitosan as a permeation enhancer to address issues related to gastric ulcers and frequent dosing. Matrix-type piroxicam patches were prepared using chitosan and glycol chitosan in various ratios to achieve controlled drug release and enhanced skin penetration. Results and Discussion: The prepared patches demonstrated consistent drug content, weight uniformity, folding endurance, tensile strength, and moisture uptake/loss values. A key novelty of the study is the use of glycol chitosan as a permeation enhancer, which significantly improved the bioavailability of piroxicam in vivo. Glycol chitosan was found to alter the protein structure of the stratum corneum and affect tight junctions in the granular layer, leading to increased water content and modification of intercellular lipids in the stratum corneum. The patches were also evaluated for stability and skin sensitivity. In vitro release studies using a Franz diffusion cell with rabbit skin revealed that the drug release kinetics followed a non-Fickian and zero-order model. Stability studies indicated no significant changes in patch characteristics over time. The formulation FPRXG6, which contained the highest concentration of glycol chitosan, exhibited maximum skin permeability and the highest plasma drug concentration (C_max = 15.87 ± 2.35 ng/mL). Conclusions: These findings suggest that the formulation enhances and prolongs bioavailability, maintaining plasma drug levels within the therapeutic range.