Drug nano- and microparticles processed into solid dosage forms: physical properties

The use of nanoparticles of relatively insoluble drugs has enormously widened the window of achievable pharmacokinetic performance. For the successful development of this technology, it is essential to understand the characteristics of nanoparticles. In this study, the processability and solid dosage performance of nanoparticulates are compared with those of microparticulates. Nanoparticle suspensions are first prepared by wet comminution in the presence of stabilizers. Spray drying converts them into dried particles from which compacts are prepared. Nanoparticles easily form aggregates during spray drying. These aggregates can be slowly redispersed into nanoparticles in water. Compacts show differences in their internal structure and micromechanical deformations, according to the size of their primary particles. Stress to break and indentation hardness are found to be only slightly higher in nanoparticulate systems.