In binary solvent: Synthesis and physicochemical studies on the nano-metric palladium(II) oxide associated from complexity of palladium(II) ions with gatifloxacin drug as a bio-precursors

Design of a Controlled-Release Delivery Composite of Antibacterial Agent Gatifloxacin by Spherical Silica Nanocarrier

In this study, a spherical silica nanoparticle was explored as a gatifloxacin carrier synthesized by the chemical precipitation method. It was found that there was no new chemical bond formation during the loading process between gatifloxacin and silica, which implies that the binding was driven by physical interaction. In addition, the drug loading and encapsulation efficiency could be improved by appropriately increasing nano-silica content in the loading process. Meanwhile, the release rate of gatifloxacin after loading nano-silica was also improved, suggesting the successful design of a controlled-release delivery composite. The silica nanocarrier could significantly improve the antibacterial performance of Escherichia coli by 2.1 times, which was higher than the pure gatifloxacin. The 24 h bacteriostatic rate was higher than that of a simple mixture of silica nanoparticles and gatifloxacin. Strong reactive oxygen species (ROS) in GAT-SiO₂ NPs suggests that ROS might be associated with bactericidal activity. The synergy between the physicochemical effect and ROS production of this material is proposed as the mechanism of its antibacterial activity, which can also be confirmed by the cell membrane damage observed under electron microscopy and DNA damage experiments. Collectively, our finding indicates that nano-silica microspheres could serve as a promising carrier for the sustained release of gatifloxacin, thereby providing a new carrier design scheme for the improvement of the antibacterial effect.

The use of complex formation manner for spectrophotometric analysis of gatifloxacin drug based on Co(II), Ni(II) and La(III) ions

Herein, a simple and accurate spectrophotometric method was developed to detect gatifloxacin (HGAT) in a pure and ophthalmic formulation. The method depends on complexation of HGAT with Co (II), Ni (II) and La(III) ions in ethanol medium at room temperature. The experimental conditions have been investigated to reach optimum conditions for HGAT-metal ions interaction, including detection of a suitable wavelength, medium pH, reaction time and reactants concentration. Moreover, the composition of these complexes in addition to their stability constants were also investigated and the result indicated that the molar ratio of HGAT: Metal ion is 1:1 for Ni (II) and La(III) ions and 1:2 for Co (II) ion. Beer's law plots were obeyed in the concentration ranges 18.77-150.16, 18.77-131.39 and 18.77-112.62 (μg mL-1) for Co(II), Ni(II) and La(III) ions interaction, respectively. The apparent molar absorptivity, Sandell's sensitivity, standard deviation, detection and quantification limits were calculated. The proposed method was successfully applied for the determination of HGAT in the bulk and ophthalmic formulation. The obtained results were compared statistically with other published methods and the results were in good agreement with those obtained by reported methods.