Formulation and evaluation of Famotidine-loaded ethosomal vesicles for ulcer therapy

Abstract

Background: Famotidine, an H₂‑receptor antagonist, suffers from variable bioavailability and frequent dosing requirements. Ethosomes, lipid‑based nanocarriers, offer improved encapsulation, stability, and sustained release.

Objective: To formulate, optimize, and characterize Famotidine‑loaded ethosomes, assessing physicochemical properties, entrapment efficiency, release behavior, kinetics, and stability.

Methods: Famotidine-loaded ethosomes were prepared using the ethanol injection method by varying the concentrations of soya lecithin and ethanol. Prior to formulation, the drug was characterized through organoleptic evaluation, solubility analysis, melting point determination, partition coefficient measurement, UV-visible spectrophotometric analysis, and Fourier-transform infrared (FTIR) spectroscopy. The prepared formulations (F1–F5) were evaluated for particle size, polydispersity index, zeta potential, scanning electron microscopy (SEM), entrapment efficiency, in vitro drug release using the dialysis bag diffusion method, release kinetics, and accelerated stability studies under ICH-recommended storage conditions.

Results: Preformulation studies confirmed the identity and purity of Famotidine, with a melting point of 154°C, λmax at 294 nm, and a partition coefficient of 2.16. FTIR analysis demonstrated the preservation of the characteristic functional groups, indicating the absence of significant chemical interactions during formulation. Among the five formulations, F4 exhibited the most desirable characteristics, with the smallest particle size (149.1 nm), zeta potential of −12.1 mV, and the highest entrapment efficiency (89.63%). SEM analysis revealed uniformly distributed, spherical vesicles with smooth surface morphology. The optimized formulation achieved 96.83% cumulative drug release within 14 h, demonstrating sustained release behaviour. Drug release followed the Higuchi diffusion model (R² = 0.979),indicating diffusion-controlled release from the vesicular matrix. Accelerated stability studies conducted for 90 days showed negligible changes in particle size and entrapment efficiency, confirming the physicochemical stability of the optimized ethosomal formulation.

Conclusion: Optimized Famotidine ethosomes showed high entrapment, sustained release, and excellent stability. Ethosomal nanovesicles are promising carriers to enhance Famotidine’s performance. Further in vivo studies are needed to confirm clinical potential.