Tween-embedded microemulsions--physicochemical and spectroscopic analysis for antitubercular drugs

Area of Science:

• Colloid and Surface Chemistry
• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Microemulsions offer potential for formulating drugs with poor solubility.
• Tuberculosis treatment requires effective drug delivery systems for drugs like isoniazid, pyrazinamide, and rifampicin.

Purpose of the Study:

• To investigate microemulsions composed of oleic acid, phosphate buffer, ethanol, and various Tweens for antitubercular drugs.
• To determine the optimal Tween surfactant for microemulsion formation and drug encapsulation.
• To characterize drug-microemulsion interactions and evaluate drug release kinetics.

Main Methods:

• Phase behavior analysis to delineate microemulsion existence regions.
• Conductivity, viscosity, and optical microscopy to study microstructural changes.
• Partition coefficient, particle size analysis, and spectroscopic techniques (UV-Vis, FTIR, 1H NMR) for drug location.
• Dissolution studies and Korsmeyer-Peppas equation for drug release kinetics.

Main Results:

• Tween 80 exhibited the maximum isotropic region, indicating optimal microemulsion formation.
• Microstructure analysis confirmed drug incorporation and its effect on the system.
• Drug release order from Tween 80 microemulsion was isoniazid > pyrazinamide > rifampicin.
• Non-Fickian release was observed for pyrazinamide and isoniazid, while rifampicin showed Fickian release.

Conclusions:

• Tween 80-based microemulsions are suitable for formulating antitubercular drugs.
• Drug release mechanisms differ based on the drug's properties and interaction with the microemulsion.
• The study provides insights into optimizing microemulsion formulations for enhanced tuberculosis therapy.