Time-dependent changes in concentration of two clinically used acetylcholinesterase reactivators (HI-6 and obidoxime) in rat plasma determined by HPLC techniques after in vivo administration

Anal Sci. 2010 Jan;26(1):63-7. doi: 10.2116/analsci.26.63.


A simple and reliable HPLC method for determination of rat plasma levels of clinically used acetylcholinesterase (AChE) reactivators (HI-6 and obidoxime) is presented in our study. Separation was carried out by HPLC using an octadecyl silica stationary phase and a mobile phase consisting of 24% acetonitrile and containing 5 mM sodium octanesulfonate and 5 mM tetramethylammonium chloride (pH 2.3). Following intramuscular administration of equimolar doses of both oximes (22.23 mg/kg), the maximum of HI-6 concentration in rat plasma was reached in about 20 min giving 15.26 +/- 1.71 microg/mL. The distribution of obidoxime was fast; the single maximum 23.62 +/- 3.563 microg/mL was recorded at about 10 min. HPLC with UV detection presented in our study is a general method which could be applied for quick measurements of bisquaternary AChE reactivators in rat plasma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Proteins / chemistry
  • Calibration
  • Cholinesterase Reactivators / blood*
  • Cholinesterase Reactivators / pharmacokinetics*
  • Chromatography, High Pressure Liquid
  • Indicators and Reagents
  • Injections, Intramuscular
  • Male
  • Obidoxime Chloride / blood*
  • Obidoxime Chloride / pharmacokinetics*
  • Oximes / blood*
  • Oximes / pharmacokinetics*
  • Pyridinium Compounds / blood*
  • Pyridinium Compounds / pharmacokinetics*
  • Rats
  • Rats, Wistar
  • Reproducibility of Results
  • Spectrophotometry, Ultraviolet
  • Trichloroacetic Acid / chemistry


  • Blood Proteins
  • Cholinesterase Reactivators
  • Indicators and Reagents
  • Oximes
  • Pyridinium Compounds
  • Obidoxime Chloride
  • Trichloroacetic Acid
  • asoxime chloride