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Comparative Evaluation of Hydrogen Peroxide Sporicidal Efficacy Bdifferent Standard Test Methods Publisher



Sadeghi S1 ; Abdollahi S2 ; Tarighi P3 ; Samadi N1, 4
Authors
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Authors Affiliations
  1. 1. Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
  2. 2. Department of Pharmaceutics, Faculty of Pharmacy, Lorestan University of Medical Sciences, Khorramabad, Iran
  3. 3. Department of Medical Biotechnology, School of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
  4. 4. Pharmaceutical Quality Assurance Research Center, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran

Source: Iranian Journal of Microbiology Published:2020


Abstract

Background and Objectives: There are different sporicidal standard tests with various specifications to deal with products that are claimed for sporicidal activity. The aim of this study was to compare the 7% H2O2 sporicidal efficacy against Bacillus subtilis spores using different standard test methods. Materials and Methods: The 7% H2O2 sporicidal efficacy against Bacillus subtilis spores was determined according to the AOAC MB-15-04 standard of carrier test and two standard suspension tests (BS EN 13704, AFNOR NF 72-230) in both clean and dirty conditions and by using different interfering substances including bovine serum albumin, yeast extract and skimmed milk. Results: The results of suspension tests with 3 × 105 and 2 × 107 CFU/ml of B. subtilis spore concentration demonstrated that the higher spore counts lead to lower efficacy of 7% H2O2. Also, the sporicidal activity of 7% H2O2 was reduced in the presence of interfering substances. Bovine serum albumin, yeast, and skimmed milk showed similar interfering effects in suspension test with 3 × 105 CFU/ml. While, in suspension tests with higher initial spore count (2 × 107 CFU/ml) severity of interfering effects were intensified and distinct. Our results indicated that the carrier sporicidal test in comparison with suspension tests required more contact time to kill B. subtilis spores. Conclusion: The results of this study showed that it is reasonable to use interfering substances and inoculated carriers in accordance with actual conditions of product usage in a sporicidal test. Interfering substances may reduce the contact surface between H2O2 and test spores; therefore, the sporicidal efficacy of H2O2 was diminished. So applying suspension test in clean condition to verify the claim of sporicidal activity is strongly discouraged. © 2020, Tehran University of Medical Science. All rights reserved.