A novel soluble lornoxicam-sodium chelate monohydrate with improved plasticity and tabletability.

Lornoxicam (LOR), a BCS II nonsteroidal anti-inflammatory drug, has been clinically utilized for moderate to severe acute pain management. However, it has poor water solubility and insufficient tabletability, leading to erratic absorption and challenge in tablet processability. This study reported a novel solid state of LOR (i.e., LOR sodium chelate monohydrate, LOR-Na·H2O) with significantly improved solubility, dissolution rate and tabletability. The prepared chelate (CCDC No.: 2125157) contains LOR-, Na+, and H2O in a molar ratio of 1:1:1, where Na+ ions bridged with O(5) of amide group, and N(2) of pyridine group on LOR-, as well as O(4) on H2O through coordination bonds. LOR-Na·H2O displayed a superior dissolution rate (5 âˆ¼ 465 folds) than commercial LOR due to its increased wettability (contact angle: 74.5° vs 85.6°) and lower solvation free energy (∼2-fold). In addition, the significant improvement in tabletability was caused by high plasticity and deformability, which was attributed to its special interlayer gliding with weak bonding interactions across layers but strong coordination bonding interactions within layers. The novel LOR-Na·H2O with significantly enhanced pharmaceutical performance offers a promising strategy for further product development.

Puerarin-Na Chelate Hydrate Simultaneously Improves Dissolution and Mechanical Behavior.

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 P21, 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.

Improving Tabletability of Excipients by Metal-Organic Framework-Based Cocrystallization: a Study of Mannitol and CaCl2.

PURPOSE: To improve tabletability of pharmaceutical excipient mannitol by forming cocrystal with metal-organic framework (MOF) structure. METHODS: Mannitol was cocrystallized with CaCl2 by slurry method and solvent evaporation method. The obtained cocrystal was characterized by SCXRD, PXRD, and thermal analysis. Comparative study on tabletability between cocrystal and ß-mannitol were then conducted. Differences in tabletability were subsequently analyzed using the bonding area-bonding strength (BA-BS) model and correlated with their crystal structures. RESULTS: The prepared cocrystal contains mannitol, CaCl2 and water in molar ratio of 1:1:2 (i.e. mannitol·CaCl2·2H2O) and all the Ca2+ in the cocrystal are linked together by mannitol molecules through an infinite coordination network, demonstrating a typical MOF structure. Compared with ß-mannitol, such MOF-based cocrystal showed improved tabletability (~2-fold increased tensile strength) and reduced lamination tendency (~3-fold increased minimum compaction pressure to occur lamination). The tabletability improvement of cocrystal was dominated by its higher BS, which is attributed to stronger intermolecular interactions. The reduced lamination tendency was attributed to its lower in-die elastic recovery than ß-mannitol. CONCLUSIONS: MOF-based cocrystallization will be a promising and valuable approach to tailor mechanical properties of pharmaceutical materials in order to achieve better pharmaceutical performance.