a simple, inexpensive and efficient method was used for extraction and determination of fexofenadine and levocetirizine with three–phase hollow fiber liquid-phase microextraction and high-performance liquid chromatography. several parameters influencing the extraction recoveries such as the nature of organic extraction solvent, ph of donor and acceptor phases, stirring rate, extraction time and...

We performed in vitro experiments with the isolated rabbit parietal peritoneum to evaluate the importance of fluid stirring intensification and of chemical modification of mesothelium and interstitium to the peritoneal transport of glucose and icodextrin. We used a mathematical model of mass transport to calculate the diffusive permeability coefficient, P, in centimeters per second. In control ...

Purpose: To prepare and evaluate metformin microspheres for prolonged release. Methods: Metformin microspheres were prepared by non-aqueous solvent evaporation method using various polymers, including ethylcellulose (EC), hydroxypropyl methylcellulose (HPMC), carbopol 934P (CA) and chitosan (CH). The effect of process variables, viz, drug/polymer ratio, stirring rate and type of polymer on the ...

By changing the temperature, pH, stirring rate, or time for calcium carbonate crystallization, complex shapes of aggregated calcium carbonates formed. Such shapes have earlier been ascribed to specific interactions with specialized additives. Without polymeric additives, aggregates of vaterite transformed more rapidly into calcite aggregates under slow than under fast stirring. With an anionic ...

The present study was carried out to examine the changes in functional properties of cholesterol-removed whipping cream by beta-cyclodextrin (beta-CD) treatment. The cholesterol removal rate reached over 90% in cream before whipping in all conditions (different stirring time and speed) applied. The apparent viscosity of beta-CD treated cream after whipping increased with increased stirring time...

The main purpose of this study is developed and drug loaded nanoparticles of azelastine hydrochloride, an antiallergic drug and optimization in terms of chemical properties, drug concentration, polymer concentration, cross‐linking agent and stirring time. Nanoparticles of azelastine hydrochloride were fabricated using chitosan and sodium alginate as polymers by ionotropic pregelation method. Ca...

In this study, hollow fiber liquid phase microextraction (HF-LPME) coupled with highperformanceliquid chromatography (HPLC) with UV detection was applied for preconcentrationand determination of Diclofenac sodium in biological fluids. Parameters affecting the extractionprocess including pH of donor phase and acceptor phase, type of extraction solvent, stirring rate,extraction time, and salt add...

We analyze an example system of four coupled phase oscillators and discover a novel phenomenon that we call a “heteroclinic ratchet”; a particular type of robust heteroclinic network on a torus where connections wind in only one direction. The coupling structure has only one symmetry, but there are a number of invariant subspaces and degenerate bifurcations forced by the coupling structure, and...

Both 2,6-di(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (n-Pr-BTP), and a synergistic mixture of di(chlorophenyl)dithiophosphinic acid and tri-n-octyl phoshine oxide, are able to selectively extract trivalent actinides over lanthanides from 0.5-1 M nitric acid. We focused on clearly identifying the extraction regime (chemical or diffusional) of these extraction systems. The dependency of extractio...