title: [Determination of octreotide in human plasma by HPLC-MS with solid-phase extraction and study on the relative bioavailability of domestic and imported octreotide injections].
abstract: OBJECTIVE
  To establish an HPLC-MS method for determination of octreotide in plasma and study the relative bioavailability of domestic and imported octreotide injections.
  
  
  METHODS
  Octreotide in plasma samples were extracted with a Waters solid-phase extraction mini column. HPLC-MS was carried out using a Waters Xetrra C18 column and a mobile phase consisting of CH3 OH-1% HAc (80 : 20), the flow rate was 0.2 mL x min(-1), and the internal standard was 6, 7, 4'-OH-isoflavone, the SIR ions for quantification were m/z 1 014.4 for octreotide and m/z 317.6 for internal standard. A single dose of 200 microg of domestic or imported preparations was intramuscularly given to 18 healthy volunteers in a randomized crossover study. Octreotide concentration in plasma was determined by LC-MS method. The pharmacokinetics and bioavailability were studied.
  
  
  RESULTS
  The regressive curve was linear (r = 0.9997) within the range of 0.5 - 40 microg x L(-1) for octreotide. The pharmacokinetics parameters of domestic and imported injection were reply to one compartment model. The mean C(max) were (19 +/- 10) microg x L(-1) and (19 +/- 11) microg x L(-1), T(max) were (0.50 +/- 0.15) h and (0.52 +/- 0.20) h, T1/2 were (1.5 +/- 0.8) h and (1.5 +/- 0.8) h, AUC(0-7 h) were (50 +/- 25) h x microg x L(-1) and (50 +/- 25) h x microg x L(-1), respectively. The relative bioavailability of domestic to imported injection was 101% +/- 10%.
  
  
  CONCLUSIONS
  The method is accurat and sensible for assay of plasma octreotide concentration. The results of statistics showed the two preparations were bioequivalent.
authors.affiliation: The Second Xiangya Hospital of Central South University, Changsha 410011, China. dingjs0221@163.com
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Ding
authors.forename: Wen-Xing
authors.initials: WX
authors.lastname: Peng
authors.forename: Zu-Hua
authors.initials: ZH
authors.lastname: Zhang
authors.forename: Huan-De
authors.initials: HD
authors.lastname: Li
authors.forename: Xue-Hua
authors.initials: XH
authors.lastname: Jiang
mesh_terms: D019540:Area Under Curve; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D018592:Cross-Over Studies; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007273:Injections, Intramuscular; D015282:Octreotide / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics*
chemical_list: D015282:Octreotide