Graphene oxide/black phosphorus nanoflake aerogels with robust thermo-stability and significantly enhanced photothermal properties in air.

Here we report a new kind of three-dimensional (3D) hybrid aerogels, based on graphene oxide (GO) and black phosphorus nanoflakes (BPNFs), for the first time. Our results demonstrate that the as-prepared GO/BPNF hybrid aerogels exhibited significantly enhanced photothermal as well as electrical properties of GO aerogels due to the addition of BP. Moreover, they also possessed excellent photothermal stability under ambient conditions without any protection, which can be ascribed to the coverage of BPNFs with GO nanosheets in these aerogels. This exceptional photothermal property along with robust stability renders GO/BPNF aerogels with promising bio-related applications, such as photothermal therapy for cancer treatment.

Morphological and Crystalline Transitions in Monohydrous and Anhydrous Aripiprazole for a Long-Acting Injectable Suspension.

Many formulation and manufacturing processes can lead to morphological and crystalline transitions in many polycrystalline drugs, changing the properties of active pharmaceutical ingredients (APIs) such as solubility and physical stability which influence their therapeutic effects and safety and so limit their usefulness. Here, we report significant changes in crystal forms and morphology, including the shape and size of particles during the manufacture of off-white aripiprazole (APZ) dry powders used for long-acting and injectable suspensions. With the optimal top-down approach, powders were prepared by recrystallizing uniform monohydrous APZ (MA) and polycrystalline anhydrous APZ (AA) form III, characterized by thermal analysis, PXRD, and FT-IR. However, powders involving MA (MAP) with a lower mean size (2.126 µm), narrower distribution (span = 1.90), and higher stability compared with AA dry powders (AAP) were found to exhibit dehydration behavior and morphological changes after completion of the preparation processes based on the results of thermal analysis. In the case of APZ powders, we wished to obtain more information to guide in the industrial production and experimental design of suspensions in the future.

Stimuli-responsive HBPS-g-PDMAEMA and its application as nanocarrier in loading hydrophobic molecules.

The topic of stimuli-responsive nanocarriers for loading guest molecules is dynamic. It has been widely studied in applications including drug controlled release, smart sensing, catalysis, and modeling. In this paper, a graft copolymer (hyperbranched polystyrene)-g-poly[2-(dimethylamino)ethyl methacrylate] (HBPS-g-PDMAEMA) was synthesized and characterized by (1)H NMR and GPC. It was observed that the star-like HBPS-g-PDMAEMA formed aggregates in aqueous solution. The influence of polymer concentration, ionic strength and pH value on the aggregates in aqueous solution was investigated by using UV-vis spectroscopy and DLS analysis. The results showed that size of aggregates was affected by a corresponding stimulus. In addition, the loading ability of HBPS-g-PDMAEMA aggregates was investigated by using pyrene or Nile red as the model guest molecules by using UV-vis and fluorescence spectroscopy. The results showed that HBPS-g-PDMAEMA aggregates were capable to encapsulate small hydrophobic molecules. These newly prepared HBPS-g-PDMAEMA nanocarriers might be used in, e.g., medicine or catalysis.

Increased dissolution of disulfiram by dry milling with silica nanoparticles.

The purpose of this study was to find a suitable method to increase the dissolution of disulfiram (DSF) which is easily decomposed. The dissolution of DSF within 1 h was significantly increased from 37% to >90% by co-milling with Aerosil® 200 pharm (Aerosil) and the increased dissolution remained stable during long-term storage while there was no significant degradation of DSF. By monitoring the changes in particle size of the grinding mixture, a mosaic DSF-in-Aerosil structure was demonstrated. The core size of the mosaic DSF/Aerosil system was 3.625 µm. The particle size of DSF was reduced from 20.75 µm to ∼200 nm and the size of the mosaic DSF/Aerosil system (3.625∼7.956 µm) increased on increasing the drug-loading content. Differential scanning calorimetry and X-ray powder diffraction analysis confirmed the largely amorphous state of DSF in the mosaic drug/carrier system. Fourier transform infrared spectroscopy confirmed the presence of hydrogen bonding between DSF and Aerosil. Scanning electron microscopy and transmission electron microscopy verified the DSF-in-Aerosil relationship in the particle size determination at different size levels. The possible mechanisms of dry milling included the hypothesis that during impact and collision, DSF particles melted into the surface of Aerosil turning them into an amorphous state or they became inlayed into the interspaces of the Aerosil structure with a much smaller size.

A novel UPLC-ESI-MS/MS method for the quantitation of disulfiram, its role in stabilized plasma and its application.

Disulfiram (DSF) has been used to treat alcoholism for many years and it has been suggested to play a key role in combatting many kinds of tumors. However, disulfiram has complex pharmacokinetics and is rapidly eliminated which limits its use as a tumor treatment. Therefore, a rapid and sensitive analytical method based on ultra performance liquid chromatography coupled to electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) was developed and validated for the determination of disulfiram in rat plasma. Blood samples were pre-stabilized with a stabilizing agent and then plasma was obtained and subjected to solid phase extraction (SPE), and chromatographed on a Phenomenex Kinetex(®) XB C18 column with gradient elution using a mobile phase consisting of acetonitrile-water (containing 0.1% formic acid and 1mM ammonium acetate) at a flow rate of 0.2mL/min for 3min. Multiple reactions monitoring in positive mode was carried out with disulfiram at 296.95/115.94 and diphenhydramine (internal standard, IS) at 256.14/167.02 over a linear range from 0.6 to 1200ng/mL. The extraction recovery of disulfiram for different concentrations ranged from 75.7% to 78.3%. The intra- and inter-day precision was less than 8.93% and 12.39%, respectively, and the accuracy was within ±7.75%. The validated method was successfully applied to a pharmacokinetic study of disulfiram in rat plasma after oral administration of a dose of 180mg/kg.