Measurement and Thermodynamic Modeling of Oxaprozin Solubility in Polymers and Mixed Solutions

Measuring and modeling the solubility of drugs in different solvent systems is helpful to guide the selection of appropriate solvents at various stages of drug formulation development. In this work, the gravimetrical method was used to determine the solubility data of oxaprozin (OXA) in different compositions of water/organic solvents (methanol and ethanol) binary mixtures within the range of 293.15 to 333.15 K. Subsequently, the differential scanning calorimetry method was used to measure the solubility of the drug in polymers (Polyethylene Glycol 6000 and Polyvinylpyrrolidone K30) at above 400 K. Then, the solubility of OXA in ultrapure water and polymer aqueous solution was acquired by UV spectrophotometry or HPLC within a temperature range of 303.15 to 323.15 K. Finally, the experimental values were compared with the calculated values from the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) to investigate the prediction accuracy of this model in different complex mixed solvent systems. The average relative deviations (ARD) were used to evaluate the model performance of PC-SAFT. Furthermore, PC-SAFT combined with solid–liquid equilibrium theory not only modeled the phase behavior between pure or mixed solvents and drugs independent of the molecular weight of the solvent but also did not require any experimental data or model parameters from the ternary system to predict the phase behavior of OXA in binary solvents. The results of this work illustrate that PC-SAFT is a beneficial model in drug development

A Flexible Single-Ion Gel Electrolyte with a Multiscale Channel for the High-Performance Lithium Metal Batteries

Single-ion polymer electrolytes (SIPEs) have attracted attention due to their unique advantage in suppressing lithium dendrite growth. However, the low ionic conductivity seriously restricts the development of SIPEs. Herein, an aerogel-based SIPE with multiscale Li+ conducting channels is proposed for the first time. The microscale Li+ transport channel is constructed through the self-assembly of cyclodextrins and Li+ containing polymer, while the macroscale channel is formed via a unidirectional freeze-drying process. The obtained aerogel exhibits high thermal stability, good wettability, and outstanding mechanical properties (78% stretchability and 50% compression resilience). The aerogel electrolyte exhibits high oxidative stability (∼4.7 V), good ionic conductivity at room temperature (2.5 × 10–4 S cm–1), and high Li+ transference number (∼0.96). The Li||LiFePO4 cells deliver outstanding rate performance and long cycle life (98% capacity retention after 200 cycles at 0.2 C). This work provides new insight toward mechanically flexible and highly performing single-ion polymer electrolytes for Li metal batteries