Introduction: The top-down approach is frequently used for drug nanocrystal production. A large number of review papers have referred to the top-down approach in terms of process parameters such as stabilizer selection. However, a very important factor, that is, the influence of drug properties, has been not addressed so far.
Areas covered: This review will first discuss different nanocrystal technologies in brief. The focus will be on reviewing the different drug properties such as solid state and particle morphology on the efficiency of particle size reduction during top-down processes. Furthermore, the drug properties in the final nanosuspensions are critical for drug dissolution velocity. Therefore, another focus is the characterization of drugs in obtained nanosuspension.
Expert opinion: Drug physical properties play an important role in the production efficiency. The combinative technologies using modified drugs could significantly improve the performances of top-down processes. However, further understanding of the drug millability and homogenization will still be needed. In addition, a carefully established characterization system for nansuspension is essential.
Keywords: drug nanocrystals; drug physico-chemical properties; nanosuspension characterization; top-down process.