The electrochemical behavior of commercial clarithromycin and spectroscopic detection of its structural changes

Abstract

The aim of the present study was to examine the behavior of commercial clarithromycin, Clathrocyn (R), comparing to the results previously obtained using pure clarithromycin under the same experimental conditions. The study was performed by cyclic linear sweep voltammetry and the bulk of electrolyte was analyzed by FTIR spectroscopy and HPLC. At gold electrode, in the range of -1.2 V to 1.0 V vs. SCE in 0.05 M NaHCO3, the electrochemical determination of pure clarithromycin was previously defined by four anodic and one cathodic reproductive peaks, and commercial clarithromycin is defined by reproductive one anodic peak which appears from 0.60 to 0.80 V vs. SCE. Previously, FTIR analysis of the bulk electrolyte showed the apparent changes in pure clarithromycin molecule structure: in the ester bond of the lactone and in ethers and acetal bonds. FTIR analysis of the bulk electrolyte also showed changes in the molecule structure in commercial-tablets form of clarithromycin: indicating disappearance of lactone structure and changes of carbonyl group at position 9.