Development of nanostructured lipid carriers containing the antimicrobial ciprofloxacin for topical application

Abstract

Ciprofloxacin (CIP), a broad spectrum antibacterial agent from the fluoroquinolone family, blocks the activity of the bacterial DNA gyrase. CIP has a limited aqueous solubility and fast clearance rate. Nanostructured lipid carriers (NLC) are drug delivery carriers very appropriate to upload hydrophobic drugs, improving their bioavailability, stability and potency. This work describes the development of NLC containing CIP, their physicochemical characterization and antimicrobial activity, in vitro. NLC particles (215-355 nm) of low size polidispersion (PDI 0.08-0.31) and negative zeta potentials (|20.7-38.7| mV) were prepared; scanning electron microscopy revealed their spherical shapes and regular contour. The particles remained stable during 365 days of storage at 25°C. The encapsulation efficiency of CIP ranged from 72.5 - 95.2%, with a sustained release profile (48 h). Preliminary antimicrobial susceptibility tests revealed a 30% increase in CIP action, when encapsulated in NLC. These proof-of-concept results show the great pharmaceutical and technological potential of the developed nanoformulations. After further tests we believe that NLC-CIP can come to be a novel pharmaceutical form to potentiate the antibiotic effect, reducing its dosage and undesirable side effects.