Sonication-assisted emulsification: Analyzing different polymers in aqueous systems for microparticle preparation by...

Area of Science:

• Materials Science
• Pharmaceutical Technology
• Chemical Engineering

Background:

• Sonication-assisted emulsification is a key technique for microparticle fabrication across pharmaceutical, cosmetic, and food industries.
• The double emulsion method, particularly water-in-oil-in-water (W/O/W), is crucial for creating microparticles with specific properties.
• Understanding polymer impact on emulsification and microparticle stability is vital for optimizing production.

Purpose of the Study:

• To investigate the influence of different polymers on microparticle preparation via the W/O/W double emulsion technique.
• To analyze the effect of polymer choice on emulsification, particle size, morphology, and stability.
• To explore the utility of Focused Beam Reflectance Measurement (FBRM) for online monitoring of microparticle formation.

Main Methods:

• Microparticles were prepared using a W/O/W solvent evaporation method with dichloromethane as the solvent.
• Polymers investigated included Ethyl Cellulose (EC 4 cp), Eudragit® RS 100, Eudragit® RL 100, Poly(lactic-co-glycolic acid) (PLGA RG503H), and Polycaprolactone (PCL).
• Particle size and distribution were monitored using FBRM, and morphology was characterized by Scanning Electron Microscopy (SEM).

Main Results:

• The time required for emulsion droplet transformation into solid microparticles varied significantly with polymer type (11.5 min for EC 4 cp to 56 min for PCL).
• PCL microparticles exhibited the smallest square weighted mean chord length, though not the highest chord count.
• FBRM data indicated that larger mean particle sizes correlated with longer Chord Length Distributions (CLD) and lower particle number peaks; SEM confirmed polymer-dependent morphology.

Conclusions:

• Polymer selection critically influences the microparticle formation process, including transformation time and final characteristics.
• Sonication aids in the emulsification of polymeric systems in aqueous media.
• FBRM is a valuable tool for real-time monitoring of microparticle formation and transformation during solvent evaporation, with results strongly dependent on polymer type.