The spectrophotometric determination of lipophilicity and dissociation constants of ciprofloxacin and levofloxacin

Lentisk (Pistacia lentiscus) Oil Nanoemulsions Loaded with Levofloxacin: Phytochemical Profiles and Antibiofilm Activity against Staphylococcus spp

Most clinical isolates of both Staphylococcus aureus and Staphylococcus epidermidis show the capacity to adhere to abiotic surfaces and to develop biofilms resulting in a contribution to chronic human skin infections. Antibiotic resistance and poor biofilm penetration are the main causes of ineffective therapeutic treatment in killing bacteria within biofilms. A possible strategy could be represented by drug delivery systems, such as nanoemulsions (composed of bioactive oil, surfactant and water phase), which are useful for enhancing the drug permeation of a loaded drug inside the biofilm and its activity. Phytochemical characterization of Pistacia lentiscus oil (LO) by direct infusion Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) allowed the identification of bioactive compounds with antimicrobial properties, including fatty acids and phenolic compounds. Several monoterpenes and sesquiterpenes have been also detected and confirmed by gas chromatography-mass spectrometric (GC-MS) analysis, together providing a complete metabolomic profiling of LO. In the present study, a nanoemulsion composed of LO has been employed for improving Levofloxacin water solubility. A deep physical-chemical characterization of the nanoemulsion including hydrodynamic diameter, ζ-potential, morphology, entrapment efficiency, stability release and permeation studies was performed. Additionally, the antimicrobial/antibiofilm activity of these preparations was evaluated against reference and clinical Staphylococcus spp. strains. In comparison to the free-form antibiotic, the loaded NE nanocarriers exhibited enhanced antimicrobial activity against the sessile forms of Staphylococcus spp. strains.

Synthesis and characterization of pH-sensitive nanocarrier based chitosan-g-poly(itaconic acid) for ciprofloxacin delivery for anti-bacterial application

This study aims to develop pH-sensitive and controlled release of ciprofloxacin from ciprofloxacin-loaded grafted chitosan-coated zinc oxide nanoparticles (Cip@Gchit/Zn-NPs) for the treatment of bacterial infections in the human colon. For this aim, first, the chitosan-g-poly(itaconic acid) [Chit-g-poly (Itac)] was synthesized via grafting of itaconic acid onto chitosan in the presence of cerium ammonium nitrate (CAN) under an inert atmosphere using conventional methods, while zinc oxide nanoparticles (Zn-NPs) were prepared via sol-gel technique. Characterization of the synthesized Cip@Gchit/Zn-NPs was analyzed using XRD, FT-IR, SEM, TGA, and zeta potential analysis. The antibacterial efficacy of Cip@Gchit/Zn-NPs against three pathogenic bacteria, namely Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, was superior to that of tetracycline reference drugs, as evidenced by larger inhibition zones. Cytotoxicity assessment of Cip@Gchit/Zn-NPs on the human chondrocyte cell line C28/I2 via MTT assay revealed 100 % cell viability at a concentration of 500 μg/mL. The loading efficiency of ciprofloxacin into Gchit/Zn-NPs was evaluated at various ratios, demonstrating lower loading efficiency; however, sustained release of ciprofloxacin from Cip@Gchit/Zn-NPs was excellent, with 98.13 % release observed at pH 7.2 over 10 h. Kinetic analysis of ciprofloxacin release followed the first-order kinetic models.

Nitrocellulose for Prolonged Permeation of Levofloxacin HCl-Salicylic Acid In Situ Gel

Currently, the application of solvent exchange-induced in situ gel is underway for drug delivery to the body target site. Nitrocellulose was attempted in this research as the matrix-forming agent in solvent exchange-induced in situ gel for acne and periodontitis treatments. The gel incorporated a combination of 1% w/w levofloxacin HCl and 2% w/w salicylic acid as the active compounds. In order to facilitate formulation development, the study explored the matrix-forming behavior of different concentrations of nitrocellulose in N-methyl pyrrolidone (NMP). Consequently, their physicochemical properties and matrix-forming behavior, as well as antimicrobial and anti-inflammatory activities, were evaluated using the agar cup diffusion method and thermal inhibition of protein denaturation in the egg albumin technique, respectively. All prepared formulations presented as clear solutions with Newtonian flow. Their contact angles on agarose gel were higher than on a glass slide due to matrix formation upon exposure to the aqueous phase of agarose, with an angle of less than 60° indicating good spreadability. Nitrocellulose concentrations exceeding 20% initiated stable opaque matrix formation upon contact with phosphate buffer pH 6.8. The high hardness and remaining force of the transformed gel indicated their robustness after solvent exchange. Fluorescence tracking using sodium fluorescein and Nile red confirmed the retardation of NMP and water diffusion by the nitrocellulose matrix. From the Franz cell permeation study, these drugs could permeate through neonate porcine skin and tissue of porcine buccal from the nitrocellulose in situ forming gel. Their accumulation in these tissues might enable the inhibition of the invading bacterial pathogens. The developed in situ gels effectively inhibited Staphylococcus aureus, Staphylococcus epidermidis, Propionibacterium acnes, and Porphyromonas gingivalis. Furthermore, the formulations demonstrated an anti-inflammatory effect. The low viscosity of LvSa25Nc makes it appropriate for injectable treatments targeting periodontitis, while the higher viscosity of LvSa40Nc renders it appropriate for topical applications in acne treatment. Therefore, the nitrocellulose in situ gel loaded with combined levofloxacin HCl and salicylic acid emerges as a promising dosage form for treating acne and periodontitis.

Bimetallic metal organic framework/Ni doped ZnO nanomaterials modified carbon paste electrode for selective electrochemical determination of ciprofloxacin

In this work, an efficient and sensitive electrochemical sensor for the determination of ciprofloxacin (CIP) is reported. The sensor was prepared by using a carbon paste electrode (CPE) modified with a combination of bimetallic copper/cerium-based metal organic framework (Cu/Ce-MOF) and nickel doped zinc oxide nanoparticles (NZP). The modifiers were characterized by Brunauer-Emmett-Teller (BET) analysis, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and elemental mapping analysis (EDS). The electrochemical behavior of the modified electrode was studied by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The developed electrode was employed for the detection of CIP by differential pulse voltammetry (DPV). Under optimal conditions, the anodic peak current response of the electrode was linearly correlated with CIP concentration in the range of 0.75-100 μmol L-1 with a sensitivity of 1.29 μA μmol-1 L-1. The limit of detection and reproducibility of the method were 0.142 μmol L-1 and 2.7%, respectively. The developed sensor showed good selectivity to CIP against possible interferents. The method was applied to determine CIP in water, milk and urine samples. The results indicated that this method has potential to be applied in the analysis of residue CIP in complex matrices with high selectivity, and good reproducibility.

The Chemometric Evaluation of the Factors Influencing Cloud Point Extraction for Fluoroquinolones

This study aimed to analyze the factors that impact the cloud point extraction of ciprofloxacin, levofloxacin, and moxifloxacin. The following independent variables were analyzed: Triton X-114 concentration, NaCl concentration, pH, and incubation temperature. The dependent variable studied was recovery. A central composite design model was used. The applied quantitation method was HPLC. The method was validated for linearity, precision, and accuracy. The results underwent ANOVA^® analysis. The polynomial equations were generated for each analyte. The response surface methodology graphs visualized them. The analysis showed that the factor most affecting the recovery of levofloxacin is the concentration of Triton X-114, while the recovery of ciprofloxacin and moxifloxacin is most affected by pH value. However, the concentration of Triton X-114 also plays an important role. The optimization resulted in the following recoveries: for ciprofloxacin, 60%; for levofloxacin, 75%; and for moxifloxacin, 84%, which are identical to those estimated with regression equations-59%, 74% and 81% for ciprofloxacin, levofloxacin, and moxifloxacin, respectively. The research confirms the validity of using the model to analyze factors affecting the recovery of the analyzed compounds. The model allows for a thorough analysis of variables and their optimization.

In Vitro and In Vivo Biological Activities of Dipicolinate Oxovanadium(IV) Complexes

The work is focused on anticancer properties of dipicolinate (dipic)-based vanadium(IV) complexes [VO(dipic)(N^∩N)] bearing different diimines (2-(1H-imidazol-2-yl)pyridine, 2-(2-pyridyl)benzimidazole, 1,10-phenanthroline-5,6-dione, 1,10-phenanthroline, and 2,2'-bipyridine), as well as differently 4,7-substituted 1,10-phenanthrolines. The antiproliferative effect of V(IV) systems was analyzed in different tumors (A2780, HCT116, and HCT116-DoxR) and normal (primary human dermal fibroblasts) cell lines, revealing a high cytotoxic effect of [VO(dipic)(N^∩N)] with 4,7-dimethoxy-phen (5), 4,7-diphenyl-phen (6), and 1,10-phenanthroline (8) against HCT116-DoxR cells. The cytotoxicity differences between these complexes can be correlated with their different internalization by HCT116-DoxR cells. Worthy of note, these three complexes were found to (i) induce cell death through apoptosis and autophagy pathways, namely, through ROS production; (ii) not to be cytostatic; (iii) to interact with the BSA protein; (iv) do not promote tumor cell migration or a pro-angiogenic capability; (v) show a slight in vivo anti-angiogenic capability, and (vi) do not show in vivo toxicity in a chicken embryo.

Drug–Membrane Interaction as Revealed by Spectroscopic Methods: The Role of Drug Structure in the Example of Rifampicin, Levofloxacin and Rapamycin

We have investigated the nature of the interaction of small organic drug molecules with lipid membranes of various compositions. Using infrared spectroscopy and differential scanning calorimetry methods, we studied the role of the structure of the active molecule in interaction with the membrane using the example of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylcholine:cardiolipin (DPPC:CL) liposomes. We discovered the key role of the heterocycle in interaction with the polar part of the bilayer and the network of unsaturated bonds in interaction with the hydrophobic part. For rifampicin and levofloxacin, the main binding sites were phosphate and carbonyl groups of lipids, and in the case of anionic liposomes we found a slight penetration of rifampicin into the hydrophobic part of the bilayer. For rapamycin, experimental confirmation of the localization of the molecule in the region of fatty acid chains was obtained, and perturbation in the region of phosphate groups was demonstrated for the first time. The process of phase transition of liposomal forms of rifampicin and levofloxacin was studied. DPPC liposomes accelerate the phase transition when loaded with a drug. DPPC:CL liposomes are less susceptible to changes in the phase transition rate.

Physiological response of Simocephalus vetulus to five antibiotics and their mixture under 48-h acute exposure

Antibiotics, widely known as major environmental xenobiotics, are increasingly being released into ecosystems due to their essential functions in human health and production. During the COVID-19 pandemic waves, antibiotic use increases remarkably in treating bacterial coinfections. Antibiotics were initially expected only to affect prokaryotes, but recent research has shown that they can disturb the biological systems of eukaryotes, especially vulnerable aquatic creatures, through both direct and indirect processes. However, their toxicity to the freshwater cladoceran Simocephalus vetulus, an essential link in the aquatic food web, has never been evaluated. The effects of four fluoroquinolones (ciprofloxacin: CFX, ofloxacin: OFX, gatifloxacin: GFX, delafloxacin: DFX), tetracycline (TET), and a mixture of these medicines (MIX) on S. vetulus thoracic limb rate (TLR) were examined in this study. After S. vetulus was exposed to 20 and 40 mg GFX L^-1, 90% and 100% mortality rates were recorded. At 2.5-10 mg L^-1, GFX dramatically lowered the TLR of S. vetulus, resulting in a median effective concentration of 9.69 mg L^-1. TLRs increased when the organisms were exposed to 10-40 mg L^-1 of CFX and 1.25-40 mg L^-1 of OFX. However, DFX and TET exposures did not affect TLRs. Exposure to MIX reduced TLR only at 40 mg L^-1, suggesting an antagonistic interaction among the five pharmaceuticals. This study demonstrated that S. vetulus physiological responses to antibiotics, even in the same class, are complex and elusive. Beyond a common additive concentration principle, the antagonistic interaction of antibiotic mixture indicates a high level of uncertainty in terms of ecological dangers. We initially introduce S. vetulus to ecotoxicological studies of antibiotics, presenting the species as a low-cost model for physiological investigations of environmental xenobiotics.