Characterization of cephalexin loaded nonionic microemulsions

Area of Science:

• Physical Chemistry
• Formulation Science
• Drug Delivery

Background:

• Microemulsions offer potential for solubilizing poorly soluble drugs like cephalexin.
• Understanding microemulsion behavior is crucial for optimizing drug formulation.

Purpose of the Study:

• To investigate cephalexin solubilization in water/propylene glycol/sucrose laurate/ethoxylated mono-di-glyceride/isopropyl myristate/peppermint oil microemulsions.
• To evaluate the impact of microemulsion composition and interfacial factors on cephalexin solubility.

Main Methods:

• Characterization of microemulsions using volumetric parameters (density, excess volume, ultrasonic velocity, isentropic compressibility).
• Dynamic light scattering to determine hydrodynamic radius.
• Electron paramagnetic resonance spectroscopy to study interfacial properties.

Main Results:

• Cephalexin solubilization capacity increased with aqueous phase fraction up to 0.4, then decreased.
• Microemulsion structure transitioned from water-in-oil to bicontinuous to oil-in-water with increasing aqueous phase.
• Interface rigidity was influenced by water content and cephalexin presence.

Conclusions:

• Microemulsion composition significantly impacts cephalexin solubilization.
• Volumetric and interfacial analyses reveal structural transitions critical for formulation.
• These findings aid in designing effective cephalexin delivery systems.