Interaction between hydroxyethyl starch and propofol: computational and laboratorial study

Supramolecular Atropine Potentiometric Sensor

A supramolecular atropine sensor was developed, using cucurbit[6]uril as the recognition element. The solid-contact electrode is based on a polymeric membrane incorporating cucurbit[6]uril (CB[6]) as an ionophore, 2-nitrophenyl octyl ether as a solvent mediator, and potassium tetrakis (4-chlorophenyl) borate as an additive. In a MES-NaOH buffer at pH 6, the performance of the atropine sensor is characterized by a slope of (58.7 ± 0.6) mV/dec with a practical detection limit of (6.30 ± 1.62) × 10⁻⁷ mol/L and a lower limit of the linear range of (1.52 ± 0.64) × 10⁻⁶ mol/L. Selectivity coefficients were determined for different ions and excipients. The obtained results were bolstered by the docking and spectroscopic studies which demonstrated the interaction between atropine and CB[6]. The accuracy of the potentiometric analysis of atropine content in certified reference material was evaluated by the t-Student test. The herein proposed sensor answers the need for reliable methods providing better management of this hospital drug shelf-life while reducing its flush and remediation costs.

Preparation and characterization of 2-hydroxyethyl starch microparticles for co-delivery of multiple bioactive agents

The present study reports the generation of 2-hydroxyethyl starch microparticles for co-delivery and controlled release of multiple agents. The obtained microparticles are characterized by using Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. By using ofloxacin and ketoprofen as drug models, the release sustainability of the microparticles is examined at pH 1.2, 5.4, and 6.8 at 37 °C, with Fickian diffusion being found to be the major mechanism controlling the kinetics of drug release. Upon being loaded with the drug models, the microparticles show high efficiency in acting against Escherichia coli and Bacillus cereus. The results suggest that our reported microparticles warrant further development for applications in which co-administration of multiple bioactive agents is required.

Effects of acute bleeding followed by hydroxyethyl starch 130/0.4 or a crystalloid on propofol concentrations, cerebral oxygenation, and electroencephalographic and haemodynamic variables in pigs

Bleeding changes the haemodynamics, compromising organ perfusion. In this study, the effects of bleeding followed by replacement with hydroxyethyl starch 130/0.4 (HES) or lactated Ringer's (LR) on cerebral oxygenation and electroencephalogram-derived parameters were investigated. Twelve young pigs under propofol-remifentanil anaesthesia were bled 30 mL/kg and, after a 20-minute waiting period, volume replacement was performed with HES (GHES; N = 6) or LR (GRL; N = 6). Bleeding caused a decrease of more than 50% in mean arterial pressure (P < 0.01) and a decrease in cerebral oximetry (P = 0.039), bispectral index, and electroencephalogram total power (P = 0.04 and P < 0.01, resp.), while propofol plasma concentrations increased (P < 0.01). Both solutions restored the haemodynamics and cerebral oxygenation similarly and were accompanied by an increase in electroencephalogram total power. No differences between groups were found. However, one hour after the end of the volume replacement, the cardiac output (P = 0.03) and the cerebral oxygenation (P = 0.008) decreased in the GLR and were significantly lower than in GHES (P = 0.02). Volume replacement with HES 130/0.4 was capable of maintaining the cardiac output and cerebral oxygenation during a longer period than LR and caused a decrease in the propofol plasma concentrations.