CNH·2HBO (M·2B) is a highly promising precursor of boron nitride (BN) fibers due to its eco-friendly and low-cost fabrication. However, it is still unclear why the fibers can maintain their morphology in spite of drastic weight loss (nearly 80 wt%) during M·2B-to-BN pyrolysis. Herein, an interesting cracking and self-healing behavior of the heated M·2B fibers was observed at initial pyrolysis.
View Article and Find Full Text PDFDonepezil hydrochloride thermosensitive in situ gel for nasal delivery was prepared by using Poloxamer 407 and Poloxamer 188 as thermoreversible polymers, hydroxypropyl-β-cyclodextrin and ethylparaben as permeation enhancer and preservative, respectively. The gelation temperature and time, pH value of the gel formulation were found to meet the requirements for nasal administration. The in vitro erosion and in vitro release tests exhibited obvious drug sustained release behavior.
View Article and Find Full Text PDFThe surface hydroxyls on SiC nanosheets provide local protons, stabilize intermediates and localize photogenerated electrons in the deep photoreduction of CO2, significantly promoting the efficiency and selectivity of CH4 yield. This study describes the surface reaction for selective CO2 reduction based on both thermodynamic and kinetic requirements.
View Article and Find Full Text PDFSimvastatin is poorly bioavailable because it is practically insoluble in water and shows dissolution rate-limited absorption. Solubilizing effects of several β-cyclodextrin (βCD) derivatives such as HPβCD, SBEβCD and DMβCD on simvastatin in aqueous solution were investigated using the phase solubility technique. The solubility diagram of simvastatin with each βCD derivative could be classified as AL-type, indicating soluble complex formation of 1:1 stoichiometry.
View Article and Find Full Text PDFThe aim of this study was to prepare a nasal gel of risperidone and to investigate the pharmacokinetics and relative bioavailability of the drug in rats. Compared with oral dosing, the risperidone nasal gel exhibited very fast absorption and high bioavailability. Maximal plasma concentration (cmax) and the time to reach cmax (tmax) were 15.
View Article and Find Full Text PDFPak J Pharm Sci
November 2015
The aim of the present work was to prepare a nasal spray of bisoprolol fumarate (BF). The Pharmacokinetics and relative bioavailability of the BF nasal formulation were evaluated in Wistar rats. The BF nasal spray after administration exhibited very fast absorption and higher plasma drug concentration.
View Article and Find Full Text PDF