Antibacterial activity and physicochemical characterization of calcium-aluminium-ciprofloxacin-layered double hydroxide

A fluoroquinolone antibacterial drug, ciprofloxacin (CPX) was successfully intercalated into calcium-aluminium-layered double hydroxide (CAL) with a molar ratio of 3:1 (Ca:Al) by anion-exchange method. The successful intercalation was confirmed by powder X-ray diffraction (PXRD) pattern analysis, Fourier transform infrared spectroscopy (FTIR), elemental analysis (CHNS), and inductively coupled plasma-atomic emission spectrometry (ICP-AES). The material was also characterized by using field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), and accelerated surface area and porosity (ASAP) analysis. The basal spacing of calcium-aluminium-ciprofloxacin-layered double hydroxide (CAC) synthesized in this study is 16.2 angstrom, which resulted from the expansion of CAL due to the inclusion of CPX in the interlayer space of the CAL carrier with a loading percentage of 75.9% (w/w). The FTIR spectra of CAC show resemblance to the peaks of CAL and CPX, indicating the inclusion of the drug into the CAL interlayers. The release percentages of the drug into phosphate-buffered saline (PBS) at pH 4.8 and 7.4 are 67% and 60%, respectively, and are best described by the pseudo-second order kinetic model. The antimicrobial activity of CPX, CAL, and CAC were investigated against Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus. CAL has a prospective application as a new carrier for CPX.