Competitive cocrystallization and its application in the separation of flavonoids

A potential cocrystal strategy to tailor in-vitro dissolution and improve Caco-2 permeability and oral bioavailability of berberine

Berberine hydrochloride (BER), a promising candidate in treating tumors, diabetes and pain management, has relatively low oral absorption and bioavailability due to its low intestinal permeability. To address these challenges, we developed a BER and lornoxicam cocrystal (BLCC) by a solvent evaporation method and characterized it using X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis. Compared with BER, BLCC exhibited an instant release in pH 1.0 HCl and a sustained release up to 24 h in pH 6.8 buffer solutions and water. The Caco-2 permeability of BLCC has shown a remarkable increase compared to that of BER (i.e., Papp(a→b): 50.30 × 10-7vs 8.82 × 10-7 cm/s), which is attributed to the improved lipophilicity of BER (i.e., log P: 1.29 vs -1.83) and the reduced efflux amount of BER (i.e., ER: 1.71 vs 12.11). Furthermore, BLCC demonstrated a relative bioavailability of 410 % in comparison to the original BER, due to notably enhanced intestinal permeability of BLCC and its continuous dissolution in simulated intestinal fluid. BLCC has the potential to tailor the dissolution behavior, improve intestinal permeability, and boost the bioavailability of BER. This indicates that the cocrystal strategy holds promise as an effective approach to improving the oral absorption and bioavailability of active pharmaceutical molecules with low permeability during drug development.

An efficient cocrystallization strategy for separation of dihydromyricetin from vine tea and enhanced its antibacterial activity for food preserving application

The objective of this study was to optimize the separation and purification of dihydromyricetin (DMY) from vine tea to obtain high purity, antibacterial and antioxidant crystal forms. We developed a cocrystallization approach for separation of DMY from vine tea with easy operation and high efficiency. The type and concentration of co-formers as well as solvent for separation have been investigated in detail. Under the optimal conditions, DMY with a purity of 92.41% and its two co-crystal forms (purity >97%) can be obtained. Three DMY crystal forms had consistent and good antioxidant activities according to DPPH radical scavenging results. DMY had effective antibacterial activity against the two kinds of drug-resistant bacteria including CRAB and MRSA, and DMY co-crystals had a greater advantage than DMY itself on CRAB. This work implies that cocrystallization can be used for the DMY separation and enhanced its anti-drug-resistant bacteria activity in food preservation.

Oxymatrine-fatty acid deep eutectic solvents as novel penetration enhancers for transdermal drug delivery: formation mechanism and enhancing effect

Transdermal delivery of drugs is commonly limited by low skin permeability. The aim of the study was to synthesize deep eutectic solvents (DESs) based on oxymatrine (OMT) and fatty acids with various alkyl chain lengths (LCFAs) as novel vehicles, to solubilize the water-insoluble drug and enhance percutaneous penetration. Quercetin (QUE) was selected as a model drug. Combining differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and molecular simulations demonstrated that the formation of DESs was mediated by charge-assisted hydrogen bonding. Physicochemical properties including stability, viscosity, and solubilization capacity were also studied. Subsequently, the effect of three stable DESs on drug release and skin permeability was evaluated. The results showed that QUE was solubilized well and presented a different sustained release behavior in DESs. Meanwhile, DESs enhanced the skin permeation of OMT and QUE, which was influenced by alkyl chain lengths of LCFAs, whereas DES consisting of lauric acid (LA) exhibited the highest enhancing effect. FTIR, DSC, and molecular docking further demonstrated consistency between micro molecular mechanism and macro penetration behavior. Additionally, HaCaT cells treated with DESs showed high cell viability, suggesting their good skin safety. Taken together, OMT-LCFA DESs would be a promising penetration enhancer for transdermal drug delivery, which also provides guidance for the design of new DESs.

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∼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.