title: A novel preparation method for drug nanocrystals and characterization by ultrasonic spray-assisted electrostatic adsorption.
abstract: OBJECTIVE
  The purpose of this study was to develop a novel and continuous method for preparing a nanosized particle of drug crystals and to characterize its properties.
  
  
  METHODS
  A new apparatus was introduced to crystallize nanosized drug crystals of amitriptyline hydrochloride as a model drug. The samples were prepared in the pure state by ultrasonic spray, and elaborated deposition was completed via electrostatic adsorption. Scanning electron microscopy, X-ray powder diffraction, and atomic force microscopy were used to characterize the size of the particles; this was subsequently followed by differential scanning calorimetry.
  
  
  CONCLUSIONS
  Nanoparticles of drug crystals were successfully prepared. The size of the drug crystals ranged from 20 nm to 400 nm; the particle size of amitriptyline hydrochloride was approximately 71 nm. The particles were spherical and rectangular in shape. Moreover, the melting point of the nanoparticles decreased from 198.2°C to 196.3°C when compared to raw particle crystals. Furthermore, the agglomeration effect was also attenuated as a result of electrostatic repulsion among each particle when absorbed, and depositing on the inner wall of the gathering unit occurred under the electrostatic effect.
  
  
  CONCLUSIONS
  Ultrasonic spray-assisted electrostatic adsorption is a very effective and continuous method to produce drug nanocrystals. This method can be applied to poorly water-soluble drugs, and it can also be a very effective alternative for industrial production. Once the working parameters are given, drug nanocrystals will be produced continuously.
authors.affiliation: School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang, People's Republic of China ; Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China ; Si Chuan Research Center of New Materials, Mianyang, People's Republic of China.
authors.forename: Bing
authors.initials: B
authors.lastname: Gao
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Dunju
authors.initials: D
authors.lastname: Wang
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Qiao
authors.forename: Guangcheng
authors.initials: G
authors.lastname: Yang
authors.forename: Fude
authors.initials: F
authors.lastname: Nie
mesh_terms: D000327:Adsorption / Q000528:radiation effects; D000639:Amitriptyline / Q000138:chemical synthesis* / Q000302:isolation & purification* / Q000528:radiation effects; D003460:Crystallization / Q000379:methods*; D004339:Drug Compounding / Q000379:methods*; D004595:Electroplating / Q000379:methods*; D019220:High-Energy Shock Waves; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010316:Particle Size; D013010:Sonication / Q000379:methods*; D055672:Static Electricity
chemical_list: D000639:Amitriptyline
keywords: amitriptyline hydrochloride; continuous; nanomedicine; nanoparticles