title: The stability investigation of compound Danshen injection (a traditional medicine) with a new high-performance liquid chromatography method.
abstract: BACKGROUND
  Compound Danshen injection (CDSI, a traditional medicine) is an effective drug for the treatment of cardiovascular and cerebrovascular diseases. However, the research about its stability is absent.
  
  
  OBJECTIVE
  A new high-performance liquid chromatography method was developed to assay its main effective constituents, i.e., propanoid acid (PA), protocatechuic aldehyde (PHA), salvianolic acid B (SAB), salvianolic acid A (SAA), and rosmarinic acid (RA). Through the newly found method, the stability of CDSI was to be investigated.
  
  
  METHODS
  The analysis was performed by a reverse-phase gradient elution using an aqueous mobile phase (containing 0.1% acetic acid) modified by acetonitrile, and detection was made simultaneously at 280 nm and 325 nm. The method was validated for accuracy, precision and limits of detection. The effects of some environmental storage conditions (light and temperature) on the stability of CDSI were investigated.
  
  
  RESULTS
  This method is precise, simple, and convenient. The result showed that illumination and temperature had an obvious effect on CDSI's stability. SAA is the most unstable one among the five components. In the condition of common light, it decomposed rapidly to almost 50% after only 4 h, and 100% after 8 h. PA, RA, and PHA might come from Danshen, was also the transformed products from other components in store process.
  
  
  CONCLUSIONS
  The result indicated that the main active constituents in CDSI suffered from the illumination and temperature greatly. CDSI should be stored at low temperature and kept away from light.
authors.affiliation: Department of Pharmaceutical Engineering, Tianjin University of Commerce, Tianjin 300134, China ; Tianjin Key Laboratory of Food Biotechnology, Tianjin 300134, China.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Fengqin
authors.initials: F
authors.lastname: Bao
authors.forename: Zhixia
authors.initials: Z
authors.lastname: Zhao
authors.forename: Xiuyu
authors.initials: X
authors.lastname: Sun
authors.forename: Wuqin
authors.initials: W
authors.lastname: Qi
authors.forename: Junbo
authors.initials: J
authors.lastname: Xie
keywords: Compound Danshen injection; high-performance liquid chromatography; salvianolic acid A; stability