Combination of Roll Grinding and High-Pressure Homogenization Can Prepare Stable Bicelles for Drug Delivery.

To improve the solubility of the drug nifedipine (NI), NI-encapsulated lipid-based nanoparticles (NI-LNs) have been prepared from neutral hydrogenated soybean phosphatidylcholine and negatively charged dipalmitoylphosphatidylglycerol at a molar ratio of 5/1 using by roll grinding and high-pressure homogenization. The NI-LNs exhibited high entrapment efficiency, long-term stability, and enhanced NI bioavailability. To better understand their structures, cryo transmission electron microscopy and atomic force microscopy were performed in the present study. Imaging from both instruments revealed that the NI-LNs were bicelles. Structures prepared with a different drug (phenytoin) or with phospholipids (dimyristoylphosphatidylcholine, dipalmitoylphosphatidylcholine, and distearoylphosphatidylcholine) were also bicelles. Long-term storage, freeze-drying, and high-pressure homogenization did not affect the structures; however, different lipid ratios, or the presence of cholesterol, did result in liposomes (5/0) or micelles (0/5) with different physicochemical properties and stabilities. Considering the result of long-term stability, standard NI-LN bicelles (5/1) showed the most long-term stabilities, providing a useful preparation method for stable bicelles for drug delivery.

Palladium-catalyzed synthesis of heterocycle-containing diarylmethanes through Suzuki-Miyaura cross-coupling.

The heterocycle-containing diarylmethane synthesis from chloromethyl(hetero)arenes with (hetero)arylboron reagents was attained using the palladium/ether-imidazolium chloride system. This coupling process tolerated a diverse range of heteroaromatic moieties with sufficient catalytic activity to achieve the efficient synthesis of various diheteroarylmethanes in good to excellent yields.

Ether-imidazolium carbenes for Suzuki-Miyaura cross-coupling of heteroaryl chlorides with aryl/heteroarylboron reagents.

Easily accessible and handled ether-imidazolium chlorides were developed as ligand precursors. The coupling reactions of heteroaryl chlorides with aryl/heteroarylboronic acids and esters were catalyzed by the palladium/ether-imidazolium chloride system with high substrate tolerance to give various heterobiaryls in good to excellent yields.