Barnabás Palcsó1, Zsófia Moldován2, Károly Süvegh3, Anna Herczegh2, Romána Zelkó1
1 University Pharmacy Department of Pharmacy Administration, Semmelweis University, Budapest
2 Department of Conservative Dentistry, Semmelweis University, Budapest
3 Laboratory of Nuclear Chemistry, Eötvös Loránd University/HAS Chemical Research Center, Budapest
Introduction: Chlorine dioxide (ClO2) is a gaseous antiseptic agent, often referred to as the “ideal biocide”, based on its effectiveness against cellular and non-cellular pathogens. Bacteria are unable to develop resistance against ClO2 as its mechanism of action relies on the selective oxidation of certain amino acids essential for the organism. One of the major limitations of its medical application is that the ClO2 residence time in aqueous solution is very short due to the high volatility of the gas.
Aims: The main purpose of our study was to create a system capable of loading and gradually releasing the gas for a prolonged time, thus, increasing the duration of the antiseptic effect of chlorine dioxide at the site of action.
Method: Poly(acrylic acid) gels containing various amount of ClO2 and polymer were formulated. A two-factor, three-level face-centred central composite design was applied for the formulation. Positron annihilation lifetime spectroscopy measurements were carried out to characterize the microstructure of the gels. The ClO2 loading capacity of the gels was tracked by analytical determination of the residual concentration. A microbiological test was performed to evaluate the antibacterial properties of the gels.
Results: The release of chlorine dioxide from poly(acrylic acid) gels was significantly slower than from the aqueous solution. The polymer act as a diffusion barrier inhibiting the release of the gaseous ClO2, while the chains form an arranged supramolecular structure with the hydrated forms of chlorine dioxide thus resulting in its sustained fugacity. The latter showed optimum as a function of the polymer concentration. The ortho-positronium lifetime distributions confirmed the microstructural changes of the formulations and were in good agreement with the analytical and microbiological evaluation.
Conclusion: The application of chlorine dioxide-loaded bioadhesive gels could be a promising alternative for the effective and safe treatment of topical infections.
Doctoral School: Pharmaceutical Sciences
Program: Modern Trends in Pharmaceutical Scientific Research
Supervisor: Romána Zelkó
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