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Potential Ototopical Antiseptics for the Treatment of Active Chronic Otitis Media: An In Vitro Evaluation
Andries Francois van Straten1, Rachel Blokland1, James William Loock1
1Division of Otorhinolaryngology, Faculty of Health Sciences, University of Stellenbosch / Tygerberg Academic Hospital, Cape Town, South Africa.
Objectives:
Primary: to compare, in vitro, the antimicrobial activity of different antiseptic agents versus quinolone drops, against the common organisms of chronic otitis media.Secondary: to examine the possible role of pH on the antimicrobial activity of the antiseptic solutions.
Methods:
Three antiseptic powders (boric acid; iodine; and a 1:1 combination of these two) and four solutions (2% boric acid; 2% acetic acid; 3.25% aluminum acetate; and 5% povidone iodine) were tested against five bacteria and two fungi common in chronic otitis media, using both agar plates and the modified broth dilution method. These results were compared with the antimicrobial activity of quinolone drops.The potential role of pH of solutions was tested by reducing the acidity of the agents and repeating the broth dilution.
Results:
Of the powders, iodine, and iodine/boric acid combined, are very effective against all organisms. Boric acid powder showed moderate effectiveness against all organisms. All solutions performed poorly on the agar plates. 5% povidone iodine has good effectivity when tested with the broth dilution method. 3.25% aluminum acetate had the best activity against Pseudomonas aeruginosa.
Conclusion:
Boric acid powder and 5% povidone iodine solution show promise for clinical use. Boric acid powder has proven clinical effectiveness. 5% povidone iodine requires further clinical research. Although very effective in vitro, iodine powder is toxic to tissues and cannot be recommended for clinical use. The pH of solutions does not seem to play a significant role in their antimicrobial activity in vitro.
Insights
Boric acid powder and 5% povidone iodine show promise for treating chronic otitis media. Iodine powder was effective but too toxic for clinical use, while solution pH had no significant impact.
Area of Science:
- Otolaryngology
- Microbiology
- Antimicrobial Agents
Background:
- Chronic otitis media (COM) is a persistent infection requiring effective antimicrobial treatments.
- Identifying safe and effective topical agents for COM is crucial for clinical management.
Purpose of the Study:
- To compare the in vitro antimicrobial activity of various antiseptic agents against common COM pathogens.
- To evaluate the influence of pH on the efficacy of antiseptic solutions.
Main Methods:
- Antiseptic powders (boric acid, iodine, combination) and solutions (boric acid, acetic acid, aluminum acetate, povidone iodine) were tested.
- Antimicrobial activity was assessed using agar plates and broth dilution methods against COM bacteria and fungi.
- The effect of pH was examined by altering solution acidity.
Main Results:
- Iodine and iodine/boric acid powders demonstrated high effectiveness against all tested organisms.
- Boric acid powder showed moderate effectiveness; 5% povidone iodine solution was effective via broth dilution.
- 3.25% aluminum acetate solution exhibited the best activity against Pseudomonas aeruginosa.
Conclusions:
- Boric acid powder and 5% povidone iodine solution are promising for clinical application in COM.
- Iodine powder, despite in vitro efficacy, is unsuitable for clinical use due to toxicity.
- Solution pH did not significantly affect antimicrobial activity in this in vitro study.
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