Electrochemical Behaviour of Nifedipine and Nitrendipine in Chloroform and Chloroform-Isopropanol Mixture

Abstract

The electrochemical behavior of nifedipine (I), nitrendipine(II) and their photodegradation products has been studied by employing electrochemical techniques in chloroform and in 1:4 mixture of chloroform-isopropanol using piperidinium perchlorate (PPC) as supporting electrolyte. It has been shown that I and II undergo in a 4e, 4H+ irreversible reduction reaction, while the reduction product, phenylhydroxylamine, is oxidized in a 2e, 2H+ reversible process to an unstable nitrosophenyl compound. Photodegradation of I and II by sunlight produces a nitrosophenyl derivative which is reversibly reduced to the corresponding unstable phenylhydroxylamine. No significant change is observed in electrochemical properties of drugs by passing from chloroform to chloroform-isopropanol mixture. The possibility of analysis of I and II by dp polarography is also verified.

Keywords

• nifedipine
• nitrendipine
• chloroform
• polarography
• cyclic voltammetry