Formulation and Physicochemical Characterization of Paliperidone- Loaded Niosomal Vesicles for Improved Transdermal...

Niosomes are nonionic surfactant-based vesicular systems. Paliperidone, which is an atypical antipsychotic used in the management of schizophrenia, exhibits poor aqueous solubility and limited oral bioavailability, which could limit its therapeutic effectiveness. This study aimed to develop and optimize paliperidone (PAL)-loaded niosomal formulations for enhance transdermal delivery and improve drug release.

PAL-loaded niosomes were prepared using the thin-film hydration method using different non-ionic surfactants (Span 20, Span 60, Span 65, and Span 80) at varying cholesterol/surfactant ratios. The formulations were characterized for PS, PDI, ZP, DC, and (EE%). In vitro drug release, release kinetics, and ex vivo permeation studies were performed. Structural and physicochemical characterization of the optimized formulation was conducted using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM).

The optimized formulation (F16), composed of Span 80 and cholesterol at a ratio of (1:4), exhibited a particle size of 129.1 ± 6.6 nm, PDI of 0.26 ± 0.015, zeta potential of -15.69 ± 1.11 mV, and entrapment efficiency of 78.2 ± 1.7%. The formulation demonstrated sustained drug release, with approximately 56% released over 6 hours. Ex vivo permeation studies showed a significant enhancement in drug permeation relative to the pure drug, with higher cumulative permeation and flux.

The novel niosomal formulation F16 was chosen as the optimal formula, with an optimal cholesterol-to-surfactant ratio, due to its superior physicochemical properties and delivery efficiency, including release and skin permeation, compared with other formulas and the pure drug, making it a candidate for a patented drug delivery system.

The developed PAL-loaded niosomes represent a promising transdermal drug delivery system, offering improved drug release and permeation, potentially enhancing therapeutic outcomes in schizophrenia management.