The purpose of the present study was to investigate the effect of polyethylene glycol (PEG) molecular weights (6000, 12000 and 20000) as solid dispersion (SD) carriers on the dissolution behavior of simvastatin. SDs with various drug : carrier ratios were prepared by solvent method and evaluated for dissolution rate. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), infrared spe...

Understanding the dynamics of fixed-bed adsorption columns for modeling is a demanding task due to the strong nonlinearities in the equilibrium isotherms, interference effects of competition of solutes for adsorbent sites, mass transfer resistances between fluid phase and solid phase, and fluid-dynamic dispersion phenomena. The interplay of these effects produces steep concentration fronts, whi...

Three solvent based methods: spray drying (SD), electrospinning (ES) and air-assisted electrospinning (electroblowing; EB) were used to prepare solid dispersions of itraconazole and Eudragit E. Samples with the same API/polymer ratios were prepared in order to make the three technologies comparable. The structure and morphology of solid dispersions were identified by scanning electron microscop...

The purpose of the present study was to investigate the effect of polyethylene glycol (PEG) molecular weights (6000, 12000 and 20000) as solid dispersion (SD) carriers on the dissolution behavior of simvastatin. SDs with various drug : carrier ratios were prepared by solvent method and evaluated for dissolution rate. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), infrared spe...

An experimental study of the phase inversion behavior of liquid-liquid dispersion has been conducted in a spray extraction column for systems of toluene / water, n-hexane/water, CCl4/water, toluene /water + glycerol (25 % wt), toluene + CCl4 (25 % wt) / water and toluene / acetic acid (5 % wt)/water. The effects of physical properties, mass transfer and column geometry...

the human mdr1 gene encodes for a p-glycoprotein (pgp), which acts as an efflux pump that transports a large variety of substrates from the inside of cells to the outside until protection against xenobiotics. the g2677t/a polymorphism in exon 21 is associated with pgp expression and function in humans. the present study was aimed to determine the frequencies of this polymorphism in a healthy po...

Camellia (genus of flowering plants of fam. Theaceae) is one of the main crops in Asia, where tea and oil from leaves and seeds have been utilized for thousands of years. This plant is excellently adapted to the climate and soil of Galicia (northwestern Spain) and northern Portugal where it is grown not only as an ornamental plant, but to be evaluated as a source of bioactive compounds. In this...

Toxic metals in rice pose great risks to human health. Metal bioaccumulation in rice grains is a criterion of breeding. Rice breeding requires a sensitive method to determine metal content in single rice grains to assist the variety selection. In the present study, four toxic metals of arsenic (As), cadmium (Cd), chromium (Cr) and lead (Pb) in a single rice grain were determined by a simple and...

A multiresidue method was developed for the de termination of 16 polycyclic aromatic hydrocarbons (PAHs) in unifloral and multifloral honeys. The analytical procedure is based on the matrix solid-phase dispersion of honey on a mixture of Florisil and anhydrous sodium sulfate in small glass columns and extraction with hexane-ethyl acetate (90 + 10, v/v) with assisted sonication. The PAH residues...

Analytical methods capable of trace measurement of semivolatile organic compounds (SOCs) are necessary to assess the exposure of tadpoles to contaminants as a result of long-range and regional atmospheric transport and deposition. The present study compares the results of two analytical methods, one using pressurized liquid extraction (PLE) and the other using matrix solid-phase dispersion (MSP...