Preparation and antimicrobial activity of Azithromycin–Eudragit RS100 electrospuns

Abstract

Introduction: Azithromycin (AZI), an azalide antibiotic, is used to manage a wide range of bacterial infections .Studies have shown that antibiotics in nanocarriers may lead to increased antibacterial activity and reduced toxicity. Aim: The aim of the present study was to describe the preparation of AZI-Eudragit RS100 nanoparticles in drug:polymer ratio of 1:5 and the solution concentrations of 10% and 20% via electrospinning technique and evaluation of their in vitro antibacterial performance against Escherichia coli (PTCC 1330), Salmonella typhi (PTCC 1609), Staphylococcus aureus (PTCC 1112) and Streptococcus pneumoniae (PTCC 1240) in comparison with drug solution. Methods: Evaluation and comparisaon of the minimum Inhibitory Concentration (MIC) values of the AZI-Eudragit RS100 nanofibers and nanobeads which were prepared previously via electrospinnig method, with the untreated AZI solutions using serial macrodilution technique. Results: Nanofibers in the sizes about 100-300 nm in diameter and micro scale in length and nanobeads in the range of 100-500 nm in diameter were achieved. The minimum inhibitory concentration (MIC) of the above mentioned microorganisms showed a significant enhance in the antimicrobial effect of AZI-Eudragit RS100 nanofibers against S. pneumoniae (40 µg/ml) and S. typhi (32 µg/ml) compare to untreated AZI solutions (>160 and 128 µg/ml) respectively. The MIC values of AZI-Eudragit RS100 nanofibers against E. coli and S. aureus were the same as untreated AZI solutions ( >128 µg/ml). Conclusions: These findings are perhaps related to the more adsorption opportunity of nanofibers with higher surface area to the bacteria cell wall and providing an antibiotic depot on the bacterial surface compared to the untreated drug solution. In conclusion, it was shown that AZI-Eudragit RS100 nanofibers with enhanced or even equal antimicrobial effects against tested bacteria could be considered as a candidate for in vivo evaluations in antibiotic therapy of relevant infections.