Development and Characterization of Green Tea Catechins and Ciprofloxacin- loaded Nanoemulsion for Intravaginal Delivery to Treat Urinary Tract Infection

The aim of the present study was to develop a nanoemulsion-based delivery system containing green tea catechins called polyphenon 60 and ciprofloxacin for intravaginal delivery to treat urinary tract infection. Polyphenon 60 and ciprofloxacin were encapsulated in a single nanoemulsion system prepared using ultrasonication technique. The nanoemulsion was characterized by determining particle size, zeta potential, morphological structure and estimating in vitro release and antibacterial efficacy. To determine the in vivo pharmacokinetic parameters and intravaginal transportation of nanoemulsion in Sprague Dawley rats, gamma scintigraphy and biodistribution study was conducted with technetium pertechnetate-labelled nanoemulsion. The preliminary antibacterial investigation showed synergy between these compounds with FIC index of 0.42. The developed formulation showed zeta potential of +55.3 mV and globule size of 151.7 nm, with polydispersity index of 0.196. The percent in vitro release for polyphenon 60 at the end of 7 h was 94.8 +/- 0.9, whereas for ciprofloxacin it was 75.1 +/- 0.15 in simulated vaginal media. Antibacterial activity evaluation against extended spectrum beta lactamase and metallo beta lactamase strains revealed that nanoemulsions containing 4 and 10 mg/ml each of polyphenon 60 and ciprofloxacin effectively inhibited the growth of bacterial strains. In biodistribution study, the percent radiolabelled drug per gram was found to be 3.50 +/- 0.26 and 3.81 +/- 0.30 in kidney and urinary bladder, respectively at 3 h. From these findings it could be concluded that the developed polyphenon 60+ ciprofloxacin nanoemulsion showed antibacterial activity against Escherichia coli and was transported efficiently to the target organs through vaginal mucosa.