The purposes of this study are the polymerization of temperature-sensitive copolymers based on N-isopropyl acrylamide and 10 mol % of 2-hydroxypropylmethacrylate, characterisations of their thermal, morphological and swelling properties, as well as the analysis of potential application in drug-delivery systems. Acetaminophen, the representative of non-steroidal anti-inflammatory drugs, was used as a model drug in this study. It is a common pain relief drug, which is also used for fever treatment.
View Article and Find Full Text PDFThe objectives of this study are the synthesis of thermosensitive poly(-isopropylacrylamide--2-hydroxypropyl methacrylate), p(NiPAm-HPMet), hydrogels and the analysis of a drug-delivery system based on piroxicam, as a model drug, and synthesized hydrogels. A high pressure liquid chromatography method has been used in order to determine both qualitative and quantitative amounts of unreacted monomers and crosslinkers from polymerized hydrogels. Swelling kinetics and the order of a swelling process of the hydrogels have been analyzed at 10 and 40 °C.
View Article and Find Full Text PDFIn this study we screened twelve newly synthesised -(substituted phenyl)-2-chloroacetamides for antimicrobial potential relying on quantitative structure-activity relationship (QSAR) analysis based on the available cheminformatics prediction models (Molinspiration, SwissADME, PreADMET, and PkcSM) and verified it through standard antimicrobial testing against , , methicillin-resistant (MRSA), and . Our compounds met all the screening criteria of Lipinski's rule of five (Ro5) as well as Veber's and Egan's methods for predicting biological activity. In antimicrobial activity tests, all chloroacetamides were effective against Gram-positive and MRSA, less effective against the Gram-negative , and moderately effective against the yeast .
View Article and Find Full Text PDFIn this study, poly(-isopropylacrylamide--2-hydroxypropyl methacrylate) hydrogels were synthesized using free radical initiated copolymerization method. Four hydrogels with different cross-linker concentrations were prepared. Semi-crystalline, cross-linked copolymer networks were confirmed by FTIR, SEM and XRD analysis.
View Article and Find Full Text PDFTo complement a previous UV study, we present a quantitative evaluation of substituent effects on spectroscopic data ((1)H and (13)C NMR chemical shifts as well as FT-IR absorption frequency) applied to N,N'-bisarylmalonamides, using simple and extended Hammett equations as well as the Swain-Lupton equation. Furthermore, the DFT CAM-B3LYP/6-311+G(d,p) method was applied to study the impact of different solvents on the geometry of the molecules and their spectral data. Additionally, experimental data are correlated with theoretical results; excellent linear dependence was obtained.
View Article and Find Full Text PDFA sensitive method for determination of the eight most prescribed drugs used in combined cardiovascular therapy in Serbia was developed and optimized. The method was based on SPE followed by LC/ion trap-MS/MS with positive electrospray ionization. Parameters that affect the SPE were optimized, such as the eluent, sample pH, and sample volume.
View Article and Find Full Text PDFThe UV absorption spectra of ten N,N'-bisarylmalonamides have been recorded in the range 200-400 nm in a set of selected solvents. The solute-solvent interactions have been analyzed on the basis of the linear solvation energy relationship (LSER) concept proposed by Kamlet and Taft. The effects of substituents on the absorption spectra have been interpreted by correlating absorption frequencies with Hammett substituent constants.
View Article and Find Full Text PDFThe antioxidant and antibacterial properties of Greek oregano extracts obtained by fractional supercritical fluid extraction (SFE) with carbon dioxide were investigated and compared with the properties of essential oil obtained by hydrodistillation. According to DPPH, hydroxyl radical and superoxide anion radical scavenging activity assays, the supercritical extracts expressed stronger antioxidant activity comparing to the essential oil. The most effective was the supercritical extract obtained by fractional extraction at 30 MPa and 100°C after the volatile fraction had been extracted at lower pressure.
View Article and Find Full Text PDFLipophilicity, a very important parameter in the potential biological activities of molecules, was investigated for newly synthesized N-substituted-2-phenylacetamide derivatives. The determination was carried out in two ways: first experimentally, by applying thin-layer chromatography (TLC) on reversed-phase TLC (RPTLC) RP18F254s in the presence of one protic (methanol) and one aprotic solvent (acetonitrile) and then mathematically, by using different software packages. The intercept of the linear dependence between volume fractions of the organic solvent and the retention parameters obtained by TLC is known as the retention chromatographic constant, R(M)(0), while the slope represents the m value.
View Article and Find Full Text PDFThere is growing concern that pollution from petrochemical and oil refinery installations in Pancevo (Serbia) has increased the incidence of various diseases including cancer. The aim of our study was to investigate cancer incidence in Pancevo and to compare it with the region of central Serbia. Cancer incidence data were obtained from the corresponding Serbian Cancer Registries.
View Article and Find Full Text PDFBackground: The St John's Wort (Hypericum perforatum; Clusiaceae) has been used in traditional and modern medicine for a long time due to its high content of biologically active phenolics. The purpose of this work was to develop a method for their fractionation and identification, and to determine the most active antioxidant compounds in plant extract.
Results: An LC-MS method which enables fast qualitative and semiquantitative analysis was developed.
Acute toxicity in vivo toward rats, of nineteen N-alkyl and N-cycloalkyl fluorocetamides [F-CH(2)-C(O)-NH-R] was correlated with their structure-dependent properties. Used descriptors are: molecular weights (M(w)) and heat of formation (DeltaH(f)) of compounds; molar refractivity (CMR), lipophilicity (ClogP), Broto lipol values, virtual logP, molecular lipophilic potential (MLP), Van der Waals surfaces (VdW SAS) and hydropathicity surface (ILM) of whole molecules; Taft steric parameters (E(s)); E(s) values with Hancock corrections (E(s)(CH)) and Verloop sterimol (B(5)) and (L) parameters of alkyl and cycloalkyl residues; superdelocalizabilities and electron densities on the [NH-C(O)-CH(2)-F] fragment. Strong quantitative structure-activity relationships were assessed.
View Article and Find Full Text PDFIntroduction: Vesicoureteral reflux, urinary infection and pyelonephritic scarring represent a well known triad in pediatric practice that may lead to severe scarring of kidneys, and development of so called reflux nephropathy. Apart from standard therapeutic options (conservative treatment and surgical therapy), endoscopic correction of refluxing vesicoureteral junction has been introduced into clinical practice.
Material And Methods: This study included endoscopically treated patients with primary vesicoureteral reflux over a 9-year period, as well as certain clinical parameters.
The purpose of the present study was to model the effects of the concentration of Eudragit L 100 and compression pressure as the most important process and formulation variables on the in vitro release profile of aspirin from matrix tablets formulated with Eudragit L 100 as matrix substance and to optimize the formulation by artificial neural network. As model formulations, 10 kinds of aspirin matrix tablets were prepared. The amount of Eudragit L 100 and the compression pressure were selected as causal factors.
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