Oil-in-oil microencapsulation technique with an external perfluorohexane phase

Area of Science:

• Pharmaceutical Technology
• Materials Science

Background:

• Conventional oil/oil emulsification limits lipophilic drug encapsulation due to drug loss into the external phase.
• Developing effective microencapsulation methods is crucial for drug delivery systems.

Purpose of the Study:

• To introduce and evaluate a new microencapsulation method using perfluorohexane (PFH) as the external oil phase.
• To compare the efficacy of this PFH-based method with conventional oil/water and oil/oil methods for lipophilic drug entrapment.

Main Methods:

• Microparticles of copovidone and Eudragit RS were prepared using an oil/PFH emulsification method with ibuprofen as a model drug.
• Particle morphology and size were analyzed, and drug encapsulation rates were compared across different emulsification techniques.

Main Results:

• The oil/PFH method yielded higher encapsulation rates (86±10%) compared to ordinary oil/oil emulsification (3±1%), with oil/water showing 74±9%.
• Particle size was influenced by stirring speed, ranging from 75µm (oil/oil) to 400µm (oil/PFH).
• Morphological analysis confirmed a matrix structure for the microparticles.

Conclusions:

• Perfluorohexane is a promising external phase for microparticle preparation, offering superior lipophilic drug entrapment.
• This modified emulsification method enables the encapsulation of lipophilic drugs into various polymers without an aqueous phase.