title: Particle Image Velocimetry Evaluation of Fluid Flow Profiles in USP 4 Flow-Through Dissolution Cells.
abstract: OBJECTIVE
  To evaluate fluid flow profiles in the flow-through cell (FTC, USP apparatus 4) system with pulsatile and non-pulsatile pumps.
  
  
  METHODS
  Instantaneous velocity vectors in the dissolution cells were obtained from images sequentially captured by a particle image velocimetry (PIV) system. The data were sorted to follow the pump pulse cycle.
  
  
  RESULTS
  The analysis showed changes in the flow profiles during a pump pulse (0.5 s) at a 0.025-s interval in two sizes of cells installed in the FTC system. Supplying a slow flow from the pulsatile pump induced instantaneous downward (inner layer) and upward (outer layer) flow in the larger cell during the suction phase. Analysis at varied medium and cell temperatures strongly suggested a contribution of natural convection to the complex flow caused by relatively high cell temperature. Uniform upward flow was observed in other cells and flow rate conditions. The time-averaged vertical velocities in the cells were similar in the pulsatile and non-pulsatile pump systems.
  
  
  CONCLUSIONS
  The PIV analysis provides information on how flow rate and pump pulse affect fluid flow profiles at multiple points in flow-through dissolution cells. An appropriate temperature control should reduce the complex flow of the medium in the FTC system.
authors: Division of Drugs, National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya-ku, Tokyo, 158-8501, Japan, h.yoshida@nihs.go.jp.
authors: Hiroyuki
authors: H
authors: Yoshida
authors: Akemi
authors: A
authors: Kuwana
authors: Hiroko
authors: H
authors: Shibata
authors: Ken-Ichi
authors: K
authors: Izutsu
authors: Yukihiro
authors: Y
authors: Goda
mesh_terms: D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012212:Rheology / Q000379:methods; D012995:Solubility; D013696:Temperature
chemical_list: D004364:Pharmaceutical Preparations