Fresenius' Zeitschrift für analytische Chemie

, Volume 334, Issue 2, pp 158–161 | Cite as

Polarographic study of a benzodiazepinooxazole: Cloxazolam

  • F. J. Rodríguez
  • R. M. Jiménez
  • R. M. Alonso
Original Papers Pharmaceutical and Clinical Chemistry


The polarographic behaviour of 10-chloro-11b-(2-chlorophenyl)-2,3,7,11b-tetrahydrooxazolo[3,2-d][1,4]-benzodiazipine-6(5H)-one (cloxazolam) was studied in the pH range 1–12. Cloxazolam suffers a hydrolysis process, which can be followed by polarography. The reduction processes of cloxazolam and its hydrolysis product are irreversible and their currents are diffusion-controlled. Two polarographic methods have been developed upon the basis of the reduction of both the protonated iminium form (pH 1.45, measurement time: 10 min) and the benzophenone produced in the hydrolysis process (pH 11.75, measurement time: 15 min). The relationship between reduction peak current and concentration is linear up to at least 5.72×10−5 mol/l for both methods. A higher sensitivity was obtained for the method based on the benzophenone reduction (detection limit 5.72×10−8 mol/l; 20 ppb). The methods developed were applied to the determination of cloxazolam in its pharmaceutical formulations (Betavel, 1 mg). The method in alkaline medium was the most adequate for the determination of the compound in tablets, with errors lower than 1%.


Reduction Peak Hydrolysis Process Drop Mercury Electrode Reduction Peak Current Differential Pulse Polarography 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Polarographische Untersuchung eines Benzodiazepinoxazols: Cloxazolam


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Alonso RM, Jiménez RM, Arechaga J, Vicente F (1988) Fresenius Anal Chem 332:261–265CrossRefGoogle Scholar
  2. 2.
    Bard AJ, Faulkner LR (1980) Electrochemical methods. Fundamentals and applications. Wiley, New YorkGoogle Scholar
  3. 3.
    Carey FA, Sundberg RJ (1984) Advanced organic chemistry, 2nd edn. Plenum Press, New YorkCrossRefGoogle Scholar
  4. 4.
    Carruthers W (1978) Some modern methods of organic synthesis. Cambridge University Press, CambridgeGoogle Scholar
  5. 5.
    Fischer-Cornelssen KA (1981) Arzneim-Forsch Drug Res 31:1757–1765Google Scholar
  6. 6.
    Ikeda M, Nagei T (1982) Chem Pharm Bull 30:3810–3816CrossRefGoogle Scholar
  7. 7.
    Kuwayama T, Kurono Y, Muramatsu T, Yashiro T, Ikeda K (1986) Chem Pharm Bull 34:320–326CrossRefGoogle Scholar
  8. 8.
    March J (1985) Advanced organic chemistry, 2nd edn. McGrawHill, New YorkGoogle Scholar
  9. 9.
    Melón A, Alonso RM, Jiménez RM (submitted for publication)Google Scholar
  10. 10.
    Miyadera T; Terada A, Fukunaga M, Kuwano Y, Kamiuna T, Tamura C, Takagi H, Tachitawa R (1971) J Med Chem 14:520–526CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • F. J. Rodríguez
    • 1
  • R. M. Jiménez
    • 1
  • R. M. Alonso
    • 1
  1. 1.Departamento de Química, Facultad de CienciasUniversidad del Pais VascoBilbaoSpain

Personalised recommendations