Bioequivalence of Two 6-Mercaptopurine Tablet Formulations in Healthy Fasting Chinese Volunteers.

The supply of branded 6-mercaptopurine (6-MP) is limited in China, necessitating the local production and clinical evaluation of generic alternatives. We evaluated the in vivo bioequivalence (BE) of a new generic mercaptopurine tablet (50 mg) formulation by comparing peak plasma concentration and area under the concentration-time curve (AUC) with a branded 6-MP formulation as the reference in 36 healthy fasting Chinese adults. The in vivo BE was evaluated by the average BE test. The safety parameters of the test and reference formulations were also evaluated. The geometric mean ratios for AUC over the dosing interval and AUC from time zero to infinity were 104% and 104%, respectively, of the reference values, while the point estimate of the geometric mean ratio for peak plasma concentration was 104% of the reference value. The test and reference formulations in this study were both deemed safe as only 23 Grade 1 adverse events were observed in 13 of 36 subjects. The test and reference formulations of 6-MP tablets meet the regulatory criteria for BE in healthy fasting Chinese adults.

Stable and recyclable FeS-CMC-based peroxydisulfate activation for effective bisphenol A reduction: performance and mechanism.

In this study, a novel material, iron sulfide modified by sodium carboxymethyl cellulose (FeS-CMC), was successfully synthetized for peroxydisulfate (PDS) activation to remove bisphenol A (BPA). Characterization results showed that FeS-CMC had more attachment sites for PDS activation due to its higher specific surface area. A stronger negative potential contributed to preventing nanoparticles from reuniting in the reaction and improving the interparticle electrostatic interactions of the materials. Fourier transform infrared spectrometer (FTIR) analysis of FeS-CMC suggested that the coordination of the ligand for combining sodium carboxymethyl cellulose (CMC) with FeS was monodentate. A total of 98.4% BPA was decomposed by the FeS-CMC/PDS system after 20 min under optimized conditions (pH = 3.60, [FeS-CMC] = 0.05 g/L and [PDS] = 0.88 mM). The isoelectric point (pHpzc) of FeS-CMC is 5.20, and FeS-CMC contributed to reducing BPA under acidic conditions but showed a negative effect under basic conditions. The presence of HCO3-, NO3- and HA inhibited BPA degradation by FeS-CMC/PDS, while excess Cl- accelerated the reaction. FeS-CMC exhibited excellent performance in oxidation resistance with a final removal degree of 95.0%, while FeS was only 20.0%. Furthermore, FeS-CMC showed excellent reusability and still reached 90.2% after triple reusability experiments. The study confirmed that the homogeneous reaction was the primary part of the system. Surface-bound Fe(II) and S (-II) were found to be the major electron donors during activation, and the reduction of S (-II) contributed to the cycle of Fe(III)/Fe(II). Sulfate radicals (SO4•-), hydroxyl radicals (•OH), superoxide radicals (O2•-) and singlet oxygen (1O2) were produced at the surface of FeS-CMC and accelerated the decomposition of BPA. This study offered a theoretical basis for improving the oxidation resistance and reusability of iron-based materials in the presence of advanced oxidation processes.

Enhanced electrochemical-activation of H2O2 to produce •OH by regulating the adsorption of H2O2 on nitrogen-doped porous carbon for organic pollutants removal.

The heterogeneous Fenton oxidation is regarded as a promising technology for refractory organic pollutants removal relying on highly active •OH generated via the decomposition of H2O2 catalyzed by iron-based catalyst that overcomes the issues of pH limitation and iron sludge discharge encountered in conventional Fenton reaction. However, the efficiency of •OH production in heterogeneous Fenton remains low as the limited mass transfer between H2O2 and catalysts caused by the poor H2O2 adsorption. Here, a nitrogen-doped porous carbon (NPC) catalyst with tunable N configuration was prepared for electrochemical-activation of H2O2 to •OH by enhancing the H2O2 adsorption on catalysts. The resultant •OH production yield on NPC reached 0.83 mM in 120 min. Notably, the NPC catalyst could be more energy-efficient for actual coking wastewater treatment with an energy consumption of 10.3 kWh kgCOD-1 than other electro-Fenton catalysts reported (20-29.7 kWh kgCOD-1). Density function theory (DFT) revealed that highly efficient •OH production was ascribed to the graphitic N which enhances the adsorption energy of H2O2 on NPC catalyst. This study provides new insight into the fabrication of efficient carbonaceous catalysts by rationally modulating electronic structures for refractory organic pollutants degradation.