title: Preparation and in-vitro evaluation of indomethacin nanoparticles.
abstract: OBJECTIVE
  During the last two decades one of the most important problems in drug formulations has been low aqueous solubility of new molecules. However, numerous techniques, such as milling, co-solvent solubilization and solid dispersion have been used conventionally for aqueous solubility enhancement and the rate of solubility. Recently, nanoparticle engineering processes have been developed and reported for pharmaceutical applications to increase the dissolution rate of low-soluble drugs which in turn may leads to substantial increases in bioavailability. In this study, a controlled precipitation method was used to produce indomethacin nano-solid suspension in a polymeric matrix (as a model), in order to increase the solubility and rate of the dissolution of poorly soluble model drug.
  
  
  METHODS
  Nano-solid suspension of indomethacin in polyvinyl pyrrolidine (PVP) was prepared by controlled precipitation technique, characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and evaluated for in vitro solubility and dissolution rate.
  
  
  CONCLUSIONS
  Absence of thermal and diffractional peaks in DSC and XRD studies indicated that indomethacin interacts with PVP in solid phase. The solubility of indomethacin in nano-solid suspension compared to crystalline form was increased to about four-fold. It was found that particle size distribution depend to the polymer MW and drug: polymer ratios. Spectroscopy methods and Transmission Electron Microscopy (TEM) images showed that indomethacin dispersed as amorphous nanosize particles in freeze dried powder. Enhanced solubility and dissolution rate of indomethacin compared to physical mixtures and crystalline form of indomethacin (polymorph I), demonstrated that it interacts with PVP via hydrogen bond and probably forming eutectic mixture.
authors.affiliation: Department of formulation and packaging of human biological products, Razi vaccine & serum research institute, Karaj.
authors.forename: A
authors.initials: A
authors.lastname: Rezaei Mokarram
authors.forename: A
authors.initials: A
authors.lastname: Kebriaee Zadeh
authors.forename: M
authors.initials: M
authors.lastname: Keshavarz
authors.forename: A
authors.initials: A
authors.lastname: Ahmadi
authors.forename: B
authors.initials: B
authors.lastname: Mohtat