Comprehensive Characterisation of the Ketoprofen-β-Cyclodextrin Inclusion Complex Using X-ray Techniques and NMR Spectroscopy

Investigation of the Affinity of Ceftobiprole for Selected Cyclodextrins Using Molecular Dynamics Simulations and HPLC

This paper presents the theoretical calculations of the inclusion complex formation between native ceftobiprole, a promising antibiotic from the cephalosporin group, and selected cyclodextrins (CDs) approved by the European Medicines Agency. Ceftobiprole was studied in three protonation states predicted from pKa calculations, along with three selected CDs in a stoichiometric ratio of 1:1. It was introduced into the CD cavity in two opposite directions, resulting in 18 possible combinations. Docking studies determined the initial structures of the complexes, which then served as starting structures for molecular dynamics simulations. The analysis of the obtained trajectories included the spatial arrangement of ceftobiprole and CD, the hydrogen bonds forming between them, and the Gibbs free energy (ΔG) of the complex formation, which was calculated using the Generalised Born Surface Area (GBSA) equation. Among them, a complex of sulfobutyl ether- (SBE-) β-CD with protonated ceftobiprole turned out to be the most stable (ΔG = -12.62 kcal/mol = -52.80 kJ/mol). Then, experimental studies showed changes in the physiochemical properties of the ceftobiprole in the presence of the CDs, thus confirming the validity of the theoretical results. High-performance liquid chromatography analysis showed that the addition of 10 mM SBE-β-CD to a 1 mg/mL solution of ceftobiprole in 0.1 M of HCl increased the solubility 1.5-fold and decreased the degradation rate constant 2.5-fold.

An electrostatic self-assembly approach to prepare tebuconazole nanoparticles with improved sustained release and enhanced antifungal activity

Compared with the traditional pesticides, the nanopesticides (NPs) exhibit better sustained release performance, higher utilization efficiency and reduction of environmental pollution. In this study, the antifungal tebuconazole (TEB) loaded nanoparticles (TEB NPs) were prepared by electrostatic self-assembly of the positively charged poly dimethyl diallyl ammonium chloride (PDADMAC) and sulfobutylether-β-cyclodextrin (SCD) inclusion complex (TEB-SCD) with negative charge. The water solubility and thermal stability of TEB were significantly improved after forming the inclusion complex. The blank NPs and TEB NPs were both characterized by particle size, zeta potential, scanning electron microscopy (SEM), sustained release and antifungal activity. The average particle size of the TEB NPs were 411.75 ± 61.65 nm, and the polydispersity index (PDI) showed low values (< 0.3). The TEB NPs were stable for at least 28 days at 25 °C. Compared with pure TEB, TEB NPs showed the sustained release properties. In addition, TEB NPs exhibited better antifungal activity than TEB industrial concentrate (TC, 98%) and commercially available TEB suspension concentrate (SC) with the 96.33 ± 13.52% antifungal rate of fusarium graminearum. The results indicated that the TEB NPs can improve the antifungal activity and reduce environmental pollution.