Abstract
Background: Levofloxacin, a broad-spectrum fluoroquinolone antibiotic, demonstrates optimal therapeutic efficacy when absorbed in the upper gastrointestinal tract (GIT). Conventional oral formulations of levofloxacin are limited by rapid gastric transit, which reduces drug bioavailability. Gastroretentive floating microspheres represent a promising strategy to prolong gastric residence time (GRT) and achieve controlled drug release.
Objective: The present study aimed to develop and evaluate levofloxacin-loaded floating microspheres employing Eudragit RS100 and ethyl cellulose as polymeric carriers, using the emulsion solvent diffusion technique, to achieve sustained drug release and enhanced buoyancy.
Methods: Four formulations (F1–F4) were prepared at drug-to-polymer ratios of 1:1 and 1:2 using Eudragit RS100 and ethyl cellulose in dichloromethane. Polyvinyl alcohol (1% w/v) served as the aqueous emulsifying phase. Formulations were evaluated for particle size, percentage yield, drug entrapment efficiency, floating behavior, scanning electron microscopy (SEM), FTIR compatibility, in vitro drug release in pH 1.2 HCl buffer, and short-term stability.
Results: Optimized formulation F3 (Eudragit RS100; drug: polymer (1:1) demonstrated a mean particle size of 160 µm, drug entrapment efficiency of 82.39%, and buoyancy exceeding 8 hours. In vitro release studies confirmed a sustained-release profile with 97.89% cumulative drug release over 8 hours. FTIR analysis confirmed the absence of drug–excipient interactions, and SEM revealed smooth, spherical morphology. Stability studies at 25°C, 30°C, and 40°C over 90 days indicated no significant changes in drug release or physical characteristics.
Conclusion: Floating microspheres of levofloxacin prepared by the emulsion solvent diffusion method exhibited desirable gastroretentive, physicochemical, and sustained-release properties. Eudragit RS100-based formulation F3 emerged as the optimal candidate for gastroretentive controlled drug delivery.