Development and Characterization of Multiple Emulsions for EnhancedDelivery of Olmesartan Medoxomil

Introduction: This study focuses on improving the solubility and stability of Olmesartan Medoxomil by developing multiple emulsions (W/O/W). This formulation approach is aimed at enhancing its oral bioavailability and therapeutic efficacy. Materials and Methods: Nine different emulsion formulations (OME1-OME9) were developed using Span 20, Span 40, and Span 80 as primary emulsifiers and Tween 80 as a secondary emulsifier. These were chosen to provide an optimal hydrophilic-lipophilic balance (HLB) that stabilizes internal and external phases of W/O/W emulsions. The emulsions were prepared using a two-step emulsification method and evaluated for visual characteristics, globule size, zeta potential, entrapment efficiency, pH, viscosity, conductivity, in vitro and ex vivo drug release, and centrifugation stability. Results: Among the formulations, OME6 exhibited the most favorable properties with a droplet size of 2.4 μm, high entrapment efficiency (88.7 ± 1.2%), drug content (95.4 ± 1.0%), and in vitro drug release of 94.3% over 12 hours in phosphate buffer (pH 6.8). The zeta potential of -29.5 mV indicated high colloidal stability. Drug release followed Higuchi kinetics, confirming controlled and sustained release behavior. Discussion: The optimized formulation OME6 demonstrated superior physical stability, efficient drug encapsulation, and sustained drug release. Its composition offered a balanced hydrophiliclipophilic environment that enhanced droplet uniformity and minimized coalescence. These features are favorable for the oral delivery of poorly water-soluble drugs like Olmesartan Medoxomil. Conclusion: OME6 is a promising multiple emulsion system for enhancing the oral delivery of Olmesartan Medoxomil, offering improved solubility, stability, and prolonged drug release, potentially leading to better therapeutic outcomes.