Simultaneous Quantitative Analysis of Clarithromycin and Ranitidine, Probe Inhibitors of P-Glycoprotein and OCT1, to Evaluate Potential Pharmacokinetic Influence of Potential Transporter Substrates

Adsorption of clarithromycin on polystyrene nanoplastics surface and its combined adverse effect on serum albumin

Emerging contaminants, such as antibiotics and nanoplastics, have garnered significant attention due to their potential adverse effects on diverse ecosystems. Antibiotic adsorption on the surface of nanoplastics potentially facilitates their long-range transport, leading to the synergistic effects of the complex. This research aims to examine the adsorption behavior of clarithromycin binding with polystyrene nanoplastics surface as well as their interaction between drug adsorbed polystyrene nanoplastics with serum albumin. Different spectroscopic methods were used to find out the interaction between clarithromycin and nanoplastics, under stimulated physiological conditions UV-vis spectroscopy showed a maximum of 22.8% percentage of the drug adsorbed with the polystyrene nanoplastics surface after 6 h of incubation. The fluorescence spectroscopic results demonstrated that the fluorescence intensity of serum albumin was quenched by the clarithromycin-polystyrene nanoplastics (CLA-PSNP) complex through static quenching. We calculated the number of binding stoichiometry, binding constants, and thermodynamic parameters. This study revealed that the CLA-PSNP binds to serum albumin spontaneously and its hydrophobic interactions played a significant role. The conformational changes in the structure of serum albumin were revealed from the findings of synchronous fluorescence spectra, CD spectra, and 3D fluorescence spectra, leading to the disturbance in functional activity. This study focuses valuable insights into the intermolecular interactions between clarithromycin-adsorbed polystyrene nanoplastics and serum albumin and its potential molecular-level biological toxicity.

Pharmacokinetic study of clarithromycin in human breast milk by UPLC-MS/MS

This study aimed to develop a validated UPLC-MS/MS method for pharmacokinetic analysis of clarithromycin in human breast milk. For sample preparation, proteins precipitated with methanol and azithromycin were used as internal standards. Clarithromycin and azithromycin detection was achieved using electrospray ionization in positive mode. The chromatographic separation time was 5 min. The lower limit of quantification was 50 ng/mL. The calibration curve of clarithromycin was 50-4000 ng/mL, with a correlation coefficient> 0.99. The method was successfully applied to determine clarithromycin levels in breast milk obtained from a lactating mother after oral administration of a single tablet containing 500 mg of clarithromycin. The maximum human breast milk concentration (C_max) was 3660 ng/mL, the time to reach the maximum concentration (t_max) was 2.5 h, and the area under curve (AUC_0-24) was 18450 ng h/mL. The present study provides a novel UPLC-MS/MS method for pharmacokinetic analysis of clarithromycin in breast milk.