Enhanced bacterial uptake and bactericidal properties of ofloxacin loaded on bioadhesive hydrogels against Pseudomonas aeruginosa

Abstract

Carbomer hydrogels 971PNF, 934PNF and 940NF loaded with ofloxacin were characterized and their antimicrobial properties evaluated. Bactericidal profiles show improved efficacy and prolonged activity exhibited by ofloxacin-containing hydrogels against Pseudomonas aeruginosa. Analysis of bactericidal index (BI) values after a short time of drug exposure confirms the higher potency of hydrogels compared with that of ofloxacin. Increased bi values observed after 24 h indicate prolonged action against the microorganisms evaluated. The bacterial uptake of ofloxacin from hydrogels was higher than that obtained with a solution of free ofloxacin in both fluoroquinolone-sensitive and -resistant P. aeruginosa. The improved uptake in fluoroquinolone-resistant isolates was correlated with the viscosity of hydrogels. The performance of hydrogels seems to be related to their bioadhesive properties that allow prolonged contact time and the release of an effective amount of drug close to bacterial cells. Hence, hydrogels could be used in the development of more effective formulations for topical administration of antibiotics. Improved performance of an old antibiotic can preserve the use of new generation fluoroquinolones.