Experimental study of the interaction of one local anesthetic with a cellulose type support

The extent of the adsorption of a local anesthetic (Bupivacaine) on a pharmaceutical adsorbent, namely microcrystalline cellulose (MCC) suspended in aqueous solution was investigated spectrophotometrically at three different temperatures. The equilibrium adsorption contact times were determined for all the temperatures and were found around 90 minutes. Adsorption isotherms have been analyzed by the Freundlich and Langmuir models. The obtained results indicated that the Freundlich isotherms presented the highest correlation coefficients, and thus they describe better the adsorption of the studied drug on MCC

Colour expression in the Cielab colour scale of new stilbene dyes

Using the well known CIELAB colour space parameters: lightness (L*), redness (a*), yellowness (b*), chroma (C*) and hue angle (h°) relative to the standard illuminants D65 (natural day light), A (tungsten light), and the standard 10° observer, the colour expression of two new symmetrical direct disazo-stilbene dyes was performed. The colour differences AEab* and AECMC were calculated against one standard, indicating a high colouring power of the both disazo-stilbene dyes. The studied dyes were synthesized using 4,4'- diaminostilbene-2,2'-disulphonic acid as middle eco-friendly component and 2-methyl-Nacetoacetanilide and 5-acetoacetylaminobenzimidazolone as coupling components respectively

Does an aromatic chloride substitute position influence the aggregation properties of direct dyes?

Dyes ions have a tendency to self-associate in aqueous solutions. The main factors influencing aggregation are dye concentration, electrolyte concentration, and temperature. In the present work, the influence of the chloride position in the dye structure on the dye aggregation was investigated. The molecular aggregation has been studied spectrophotometrically in aqueous solutions as a function of dye concentration (10'6 -s- 10"3 mol/L). As the concentration increases, different changes were observed in the dyes UV-vis spectra indicating that the molecules are beginning to aggregate. The shapes of the obtained spectra were totally different as the position of the chloride was changed in the dye molecule

Experimental study of the ibuprofene’s interaction with some natural supports

The interaction of ibuprofene with two natural solid supports (orange peel and cotton fibre) was studied at three different temperatures (25, 35 and 45 oC) aiming to establish the best theoretical adsorption model and the corresponding thermodynamic parameters (enthalpy and entropy) of the process. For the investigated systems, the time necessary for attaining the adsorption equilibrium was estimated through a series of preliminary experiments, which indicated periods of time ranging from 195 to 380 minutes. Further, the experimental data resulted from the adsorption process was fitted to the Freundlich and Langmuir classical adsorption models, but also to the Sips and Jossens isotherm models, which were not tested yet in the case of the present studied systems. The obtained results showed that for both investigated systems it was the Sips model which described better the interaction of the model drug with the investigated solid supports

Toxicological evaluation of the organic phase resulted from the COSORB process

In this work, the toxicological assesment of the organic phase resulted from the COSORB process was performed. For this purpose, an animal model was used to evaluate the effects of the organic phase on skin physiological parameters after topical application to SKH-1 hairless mice. The obtained results revealed that the constituents of the organic phase induce skin toxicity by disturbing the physiological skin parameters status, which represents the first signs of skin pathology

Photocatalytic degradation of some aqueous suspensions of propranolol

In this work, the photocatalytic degradation of Propranolol aqueous solutions of different concentrations was investigated in the presence of TiO2 and TiO2-MoO3 catalysts. Among the two photocatalysts used, the best performance can be attributed to the TiO2-MoO3 catalyst. Optimal reaction conditions were established: Ccat. = 2 g/L; CPropranolol. = 0,25 mM; V = 20 mL, lampe – sample distance = 10 cm, when the UV-A-induced photocatalytic oxidation over the Propranolol suspensions was able to degradate almost completely the studied drug. The speed of decomposition of Propranolol was accelerated when the process was carried out at a temperature of 50°C

Use of some natural supports for the adsorption of theophylline from aqueous solutions

In this work, the interaction of Theophylline with lemon peel and olive leaves (two natural solid supports) was studied at 25, 35 and 45 oC in order to identify the most appropriate theoretical adsorption model, as well as the corresponding thermodynamic parameters (free energy of Gibbs, enthalpy and entropy) of the adsorption process. In the first stage, the time necessary for attaining the equilibrium was established in a series of preliminary experiments, which indicated periods of time ranging from 182 to 356 minutes. The experimental data obtained from the adsorption process was fitted to the Freundlich and Langmuir classical adsorption models by linear regression analysis. The obtained results indicate that for both studied systems, the Langmuir model described better the interaction of Theophylline with the solid supports taken in work

Theoretical consideration regarding the contaminated soil

This artice represent a small review of the main methods for decontamination of soil infected with toxic chemicals. Are presented several methods such as: isolation of contaminated area, separation methods, electrochemical methods, phytoremediation and photocatalytic remediation of soil contaminated with toxic chemicals

Preliminary TLC studies on Posidonia oceanica seagrass

Several photosynthetic pigments, i.e. chlorophylls and carotenoids, belonging to Posidonia oceanica seagrass, were separated by thin-layer chromatography (TLC) using a hexane/acetone solvent mixture. Additionally, densitometric measurements and spectral scanning of the TLC plates were performed using the Camag TLC Scanner 3 together with the WinCATS software

Comparisons Between Tridentate Bis(benzazoles)-pyridine and Bis(benzazoles)triazine Ligands: a Theoretical Study

Twelve bis(benzazole) structures with potential ligand character were investigated by means of computational chemistry. Global and local reactivity descriptors within DFT (Density Functional Theory) theory (Fukui functions, chemical potential, hardness, electrophilicity index) have been computed at B3LYP/6-31G(d,p) level of theory. NICS(0) (Nucleus Independent Chemical Shift) index computations were employed for the evaluation of the local aromatic character of each heterocyclic moiety. Best results have been reported for the bis(benzimidazole) derivatives. Copper and zinc complexes of the investigated tridentate ligands have been proposed