Development and Characterization of Multiple Emulsions for Enhanced Delivery of Olmesartan Medoxomil
D. Maheswara Reddy, C. Nikitha, K. Geetha Devi, P.V. Sowjanya, S. Arshiya Kounain, U. Harika, Maheswara Reddy M, S. JagadeeshIntroduction:
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.