Preparation and characterization of coenzyme Q10-loaded PMMA nanoparticles by a new emulsification process based on microfluidization

A microfluidization and solvent evaporation method was employed to prepare poly(methyl methacrylate) (PMMA) nanoparticles containing coenzyme Q10. Dynamic light scattering and transmission electron microscopy showed that the mean diameter of the nanoparticles was highly influenced by the kind of surfactants used and the recycling number of the microfluidization process. Particles with sizes from 40 to 260 nm and low polydispersities were produced with good reproducibility. Despite a very high target drug loading yield, 38.7% (w/w), the actual loading efficiency reached above 95%, as demonstrated by 1H NMR analysis. Coenzyme Q10 formed a crystal structure within the polymer matrix with a melting temperature of 48 °C, as demonstrated by differential scanning calorimetry. No free drug crystals were found in the aqueous suspension of nanoparticles. A comparative study on structural stability of coenzyme Q10 showed that both UV and high temperature-induced drug inactivation were effectively hindered when the drug was encapsulated within the polymer nanoparticles.