Voltammetric studies of 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid as a novel prodrug of 5-aminosalicylic acid

Citation
B. Nigovic et al., Voltammetric studies of 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid as a novel prodrug of 5-aminosalicylic acid, J PHARM B, 26(5-6), 2001, pp. 987-994
Citations number
22
Categorie Soggetti
Chemistry & Analysis
Journal title
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
ISSN journal
07317085 → ACNP
Volume
26
Issue
5-6
Year of publication
2001
Pages
987 - 994
Database
ISI
SICI code
0731-7085(200112)26:5-6<987:VSO2AA>2.0.ZU;2-R
Abstract
The electrochemical properties of a colon-targeted prodrug of 5-aminosalicy lic acid (5-ASA), 2-hydroxy-5-[(4-sulfophenyl)azo]benzoic acid (SPSA), were investigated in aqueous solutions at glassy carbon electrodes using cyclic voltammetry and controlled potential electrolysis. The influence of the pH and experimental time domain on the reaction pathway has been studied. The electrochemical reduction of SPSA is identified as an ECE process always l eading to the cleavage of azo bond. In an acidic media SPSA is reduced in a 4e(-)/4H(+) process yielding 5-ASA and sulfanilic acid. In neutral and wea kly basic media SPSA is reduced in 2e(-)/2H(+) process resulting in the hyd razo intermediate that is stable enough to enable its reoxidation back to S PSA in the time scale of the cyclic voltammetry. (C) 2001 Elsevier Science B.V. All rights reserved.