The coamorphous tadalafil–repaglinide (molar ratio, 1 : 1) prepared by solvent-evaporation method significantly improve the physicochemical properties of tadalafil and repaglinide.

In this paper, the authors report on a novel tungsten microneedle array fabricated using deep reactive ion etching. The fabricated sample was 10 mm long, 10 mm wide, and 40 μm in pitch. Each microneedle had a top-end diameter of 7.7 μm, a bottom-end diameter of 30 μm, a length of 60 μm, and a sidewall tilt angle of approximately 14°. The mechanical strength, hydrophobicity and contact impedance of the tungsten microneedle array were characterized. For the mechanical strength, a rubbing test was conducted, which involved moving the tungsten microneedle array structure on a 800-grit abrasive paper with an equivalent slide friction force of 2 × 10−3 μN. Results indicated no obvious damage to the microneedles at the scanning electron microscopy level. Hydrophobicity test results showed that the surface of the tungsten microneedle array was uniform and hydrophobic, with an average contact angle of 137.9° and a maximum contact angle variation of 5.9° for the best sample. The contact impedance of the tungsten microneedle array sample to skin was found to be stable after 1 h of contact at a value of less than 2000 Ω in the range of 50–100 kHz.

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The assembly of nanomaterials into suprastructures offers the possibility to fabricate larger scale functional materials, whose inner structure strongly influences their functionality for a vast range of applications. In spite...

Puerarin monohydrate (PUEM), as the commercial solid form of the natural anti-hypertension drug puerarin (PUE), has low solubility, poor flowability, and mechanical properties. In this study, a novel solid form as PUE-Na chelate hydrate was prepared by a reactive crystallization method. Crystal structure analysis demonstrated that PUE-Na contains PUE − , Na + , and water in a molar ratio of 1:1:7. It crystallizes in the monoclinic space group P2 1 , and Na + is linked with PUE − and four water molecules through Na + ← O coordination bonds. Another three crystal water molecules occupy channels along the crystallographic b-axis. Observing along the b-axis, the crystal structure features a distinct tubular helix and a DNA-like twisted helix. The complexation between Na + and PUE − in aqueous solution was confirmed by the Na + selective electrode, indicating that PUE-Na chelate hydrate belongs to a type of chelate rather than organic metal salt. Compared with PUEM, PUE-Na exhibited a superior dissolution rate (i.e., ∼38-fold increase in water) owing to its lower solvation free energy and clear-enriched exposed polar groups. Moreover, PUE-Na enhanced the tabletability and flowability of PUEM, attributing to its better elastoplastic deformation and lower-friction crystal habit. The unique PUE-Na chelate hydrate with significantly enhanced pharmaceutical properties is a very promising candidate for future product development of PUE.

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