Autographic assay for the rapid detection of antioxidant capacity of liquid and semi-solid pharmaceutical formulations using ABTS•+ immobilized by gel entrapment

AAPS PharmSciTech. 2010 Sep;11(3):1159-63. doi: 10.1208/s12249-010-9484-y. Epub 2010 Jul 24.

Abstract

An autographic assay suitable for the detection of antioxidant compounds in a complex matrix (liquid and semi-solid pharmaceutical formulations) or in isolated compounds was described. The pre-formed radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(•+)) was generated by oxidation of ABTS with potassium persulfate and reduced in the presence of hydrogen-donating antioxidants. For a further comparative estimation of its applicability and sensitivity, different medicinal plant extracts, hydrogels and antioxidant compounds were dot seeded or chromatographed on silica gel (TLC) and revealed with ABTS(•+) solution (System I) or ABTS(•+) immobilized by gel entrapment (System II). Both systems were effective and able to detect antioxidant activity in a micromolar range in seconds. System II was more sensitive and reproducible than System I. This micromethod is quick, inexpensive, and particularly helpful whether it works with numerous samples or on a small scale.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antioxidants / analysis*
  • Benzothiazoles / chemistry*
  • Chromatography, Gel / methods*
  • Drug Compounding / methods
  • Drug Evaluation, Preclinical / methods*
  • Gels / chemistry
  • Pharmaceutical Preparations / analysis
  • Pharmaceutical Preparations / chemistry*
  • Plant Extracts / analysis*
  • Plants, Medicinal / chemistry*
  • Powders
  • Solutions
  • Sulfonic Acids / chemistry*

Substances

  • Antioxidants
  • Benzothiazoles
  • Gels
  • Pharmaceutical Preparations
  • Plant Extracts
  • Powders
  • Solutions
  • Sulfonic Acids
  • 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid