FDM 3D printing has been recently attracted increasing research efforts towards the production of personalized solid oral formulations. However, commercially available FDM printers are extremely limited with regards to the materials that can be processed to few types of thermoplastic polymers, which often may not be pharmaceutically approved materials nor ideal for optimizing dosage form performance of poor soluble compounds. This study explored the use of polymer blends as a formulation strategy to overcome this processability issue and to provide adjustable drug release rates from the printed dispersions. Solid dispersions of felodipine, the model drug, were successfully fabricated using FDM 3D printing with polymer blends of PEG, PEO and Tween 80 with either Eudragit E PO or Soluplus. As PVA is one of most widely used polymers in FDM 3D printing, a PVA based solid dispersion was used as a benchmark to compare the polymer blend systems to in terms processability. The polymer blends exhibited excellent printability and were suitable for processing using a commercially available FDM 3D printer. With 10% drug loading, all characterization data indicated that the model drug was molecularly dispersed in the matrices.During in vitro dissolution testing, it was clear that the disintegration behavior of the formulations significantly influenced the rates of drug release. Eudragit EPO based blend dispersions showed bulk disintegration; whereas the Soluplus based blends showed the 'peeling' style disintegration of strip-by-strip. The results indicated that interplay of the miscibility between excipients in the blends, the solubility of the materials in the dissolution media and the degree of fusion between the printed strips during FDM process can be used to manipulate the drug release rate of the dispersions. This brings new insight into the design principles of controlled release formulations using FDM 3D printing.

Pseudocapacitive behaviours of Na2Ti3O7@CNTs enhance the electrochemical performance of Na-ion capacitors with high energy density and high power density.

Flower-like antimony sulfide structures were prepared by a simple and easy polyol reflux process. When tested as an anode for sodium ion batteries, the material delivered a high reversible capacity of 835.3 mA h g(-1) at 50 mA g(-1) after 50 cycles and maintained a capacity of 641.7 mA h g(-1) at 200 mA g(-1) after 100 cycles. Even up to 2000 mA g(-1), a capacity of 553.1 mA h g(-1) was obtained, indicating an excellent cycle performance and a superior rate capability. The mechanism of the formation of the micro-flowers was also investigated. The additive used facilitates the controlled release of the reactant to form uniform, shaped nanosheets and an optimum reaction time allows the nanosheets to self-assemble into micro-flowers.

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This study has presented a series of novel approaches for the identification, quantification and prediction of phase separation in HME formulations. Supersaturation of drug in the polymer caused the phase separation of the aged felodipine-Eudragit E PO formulations.