Preparation of Nanoparticles Including Antisolvent Drugs by the 
Combination of Roll Milling and High-pressure...

Design methods of nanoparticle formulations are divided into break-down methods and build-up methods. The former is further divided into dry and wet processes. For drug nanoparticle preparations, the wet process is generally employed, and organic solvents are used in most formulations.

In this study, we investigate the preparation of nifedipine (IB) and griseofulvin (GF) nanoparticles without using organic solvent. Both IB and GF nanoparticles, with a mean particle size of approximately 50 nm, were prepared without organic solvent by employing a combination of roll milling and high-pressure homogenization.

The X-ray diffraction peak of the IB and GF samples prepared by roll milling was present at a position (2θ) identical to that of IB and GF crystals, indicating that no peak shift was induced by interaction with phospholipids.

These findings demonstrate that most IB and GF nanoparticles exist as crystals in phospholipids.