Interaction between Bifunctional Dioxo Macrocyclic Polyamine Co(II) Complex and DNA in Metallomicellar System

The cleavage of DNA (pUC18) by lipophilic macrocyclic polyamine Co(II) complex was investigated in metallomicellar system. The results showed that the conversion of plasmid DNA (pUC18) increases with the increase of the concentration of complex under physiological conditions.

Application of Bis(2-Ethylhexyl) Sulfosuccinate(AOT) /Isooctane Reverse Micellar System in Extraction of Sesame Residue Proteins

[ Objective] To investigate the factors affecting sesame residue protein extraction and find the optimum extraction conditions, [Method ] Sesame residue proteins were extracted with bis（2-ethylhexyl）sulfosuocinate （AOT）/isooctane reverse micellar system. Orthogonal test was used to screen the optimum combination of four factors including sesame residue concentration, pre-extraction pH value, potassium chloride concentration and reverse extraction time. The yield of extracted sesame residue proteins was the indicator to evaluate the efficiency of process. E Result1 The optimum extraction conditions are as follows： sesame residue concentration： 0.06 g/ml; pre-extraction pH value, 3.0; potassium chloride concentration, 1.5 mol/L; and reverse extraction time, 20 min. In the optimum extraction conditions, the extraction rate was up to 86%. [ Coaclusion] Extraction of sesame residue proteins can be well performed with AOT/isooctane reverse micellar system.

Effects of surfactants on enzyme-containing reversed micellar system

With the development of colloid interface and enzyme technologies,enzyme-containing reversed micellar system has been receiving much attention in bioseparation and bioconversion. Because of its high efficiency,it has brought new opportunities for the development of molecular biotechnology. Reversed micelles represent nano-sized aqueous droplets stabilized by surfactant amphiphiles inside the bulk organic solvents. The entrapped enzymes have enhanced activities under those conditions as suited in the lipid bilayers of biological membranes. The fundamentals of enzyme-containing reversed micellar system are described in this paper,with special emphasis on the effects of surfactants varying in concentrations and structures. The latest study progress on the surfactants application in enzyme-containing reversed micelles is reviewed. The introduction of novel functional surfactants in micellar enzymology and their future development are also discussed.

Modeling solubility of oxaprozin and irbesartan in biorelevant complex solutions based on a combination of pH-dependent and micellar solubilization models

Biological solubility is one of the important basic parameters in the development process of poorly soluble drugs,but the current measurement methods are mainly based on a large number of experiments,which are time-consuming and cost-intensive.There is still a lack of effective theoretical models to accurately describe and predict the biological solubility of drugs to reduce costs.Therefore,in this study,osaprazole and irbesartan were selected as model drugs,and their solubility in solutions containing surfactants and biorelevant media was measured experimentally.By calculating the parameters of each component using the perturbed-chain statistical associating fluid theory(PC-SAFT)model,combined with pH-dependent and micellar solubilization models,the thermodynamic phase behavior of the two drugs was successfully modeled,and the predicted results were in good agreement with the experimental values.These results demonstrate that the model combination used provides important basic parameters and theoretical guidance for the development and screening of poorly soluble drugs and related formulations.

Selective micellar electrokinetic chromatographic method for simultaneous determination of some pharmaceutical binary mixtures containing non-steroidal anti-inflammatory drugs

A simple and selective micellar electrokinetic chromatographic （MEKC） method has been developed for the analysis of five pharmaceutical binary mixtures containing three non-steroidal antiinflammatory drugs （NSAIDs）. The investigated mixtures were Ibuprofen （IP）-Paracetamol （PC）, Ibuprofen （IP）-Chlorzoxazone （CZ）, Ibuprofen （IP）Methocarbamol （MC）, Ketoprofen （KP） Chlorzoxazone （CZ） and Diclofenac sodium （DS）-Lidocaine hydrochloride （LC）. The separation was run for all mixtures using borate buffer （20 mM, pH 9） containing 15% （v/v） methanol and 100 mM sodium dodecyl sulphate （SDS） at 15 kV and the components were detected at 214 nm. Different factors affecting the electrophoretic mobility of the seven investigated drugs were studied and optimized. The method was validated according to international conference of harmonization （ICH） guidelines and United States pharmacopoeia （USP）. The method was applied to the analysis of five pharmaceutical binary mixtures in their dosage forms. The results were compared with other reported high performance liquid chromatographic methods and no significant differences were observed.

Enantiomeric Separation of Epinephrine and Salbutamol by Micellar Electrokinetic Chromatography Using β-Cyclodextrin as Chiral Additive

Enantiomeric separation of epinephrine and salbutamol was investigated by micellar electrokinetic chromatography employing β-cyclodextrin as chiral additive in ammonium chloride-ammonia solution. The analytes were detected by electrochemistry using gold microelectrode at +0.65 V versus SCE reference electrode. The effects of detection potential, concentration of β-cyclodextrin, concentration of sodium dodecyl sulfate, pH value of electrolyte and applied voltage were discussed.

New insights into the mechanism of surfactant enhanced oil recovery:Micellar solubilization and in-situ emulsification

Reducing the oil-water interfacial tension(IFT)to ultra-low is believed the primary mechanism for surfactant-based enhanced oil recovery(EOR)process.However,field trials have shown that low concentration surfactant flooding can also improve oil recovery without ultra-low IFT.To clarify the mechanism behind,the currently-used surfactant,naphthenic arylsulfonate(NAS),was used to unravel its function during surfactant flooding from the horizon of micron-and nano-scale.The solubilization capacity of NAS micelle to petroleum fractions was evaluated through light absorbance strategy,smallangle neutron scattering,dynamic light scattering and transmission electron microscopy.It was found that micellar solubilization plays a significant role during the surfactant flooding.In-situ emulsification was visualized in microfluidics with three types of microchips,respectively.A series of displacement tests were carried out with NAS solution pumping into oil-saturated chip.The results show that in-situ emulsification improve oil recovery mainly through blocking and entrainment effects.Results from this work aid in understanding the interaction between surfactant solution and petroleum fractions at low surfactant concentration,which is helpful for design surfactant-based displacing system for EOR process.

Separation of Six Pyridoncarboylxic Acid Derivatives by Micellar and Microemulsion Electrokinetic Chromatography

Micellar and microemulsion electrokinetic chromatography (MEKC & MEEKC) separation of six closely structural pyridoncarboylxic acid derivatives were studied and compared Both anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant hexadecyl-trimethyl ammonium bromide: (CTAB) were used to form micellar and microemulsion as pseudostation phases, respectively. The effects of the separation conditions on retention time and selectivity were studied. Good resolutions were obtained in selected systems. indicating that there is markably different selectivity between SDS and CTAB systems.

Pseudo Peak Phenomena in Micellar Electrokinetic Capillary Chromatography by Using Ionic Surfactant

The origin of pseudo peak was studied by means of micellar electrokinetic capillary chromatography with cetyltrimethylaminium bromide as the pseudo stationary phase. It has been pointed that two peaks may appear for one component under certain conditions. Experiments showed that the relative areas of the two peaks of analyte depended on the time and the temperature of reaction between analyte and surfactant, and the concentration of surfactant in the sample solution. It means that the interaction between the analyte and the surfactant is a slow process, and a stable substance can be produced from the interaction. It is the substance and the analyte that may lead to the formation of two peaks. The fast interaction mechanism between the solute and the micellar should be queried from the experiment result.

Simultaneous determination of ten nucleosides and bases in Ganoderma by micellar electrokinetic chromatography

Ganoderma(lingzhi)is a famous herbal medicine and edible supplement in oriental countries for a long history.In this study,a simple micellar electrokinetic chromatography(MEKC)method was established for the analysis of nucleosides and bases,the major bioactive components in Ganoderma for the first time.By optimizing the borate concentration,the sodium dodecyl sulfate(SDS)concentration and the pH value of running buffer,10 nucleosides and bases achieved an ideal separation.In real sample analysis,the developed method was successfully used to determine the 10 target analytes in 23 batches of Ganoderma samples from different regions.Results indicated that contents of 10 investigated analytes in each sample showed obvious variation.The principal components analysis(PCA)and hierarchical cluster analysis(HCA)analysis classified the samples into three groups,and the HCA tree visualized the relationships which was mainly contributed by geographical partition.The results indicated geographical origin to be an important factor that affect the accumulation of nucleosides and bases in Ganoderma.In summary,this study provides a simple and practical strategy for quality assessment and cultivation reference of Ganoderma.

Flow-injection spectrophotometric determination of vanadium with malachite green oxalate by bromate in acidic and micellar medium

A flow injection method is proposed for determining vanadium（V）. The method is based on its catalytic effect on the oxidation of malachite green oxalate by bromate. The reaction was monitored spectrophotometrically by measuring malachite green oxalate absorbance at λmax = 625 nm. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine vanadium in the ranges of 10-140 ng/mL with a detection limit of 5.2 ng/mL and a sample rate of 20 ± 5 samples/h.

A Highly Sensitive Kinetic Spectrophotometric System and Its Analytical Potential for Chromatographic Detection of Metal Ions

Based on the inhibitory effect of metal ions on the decolourization reaction of a dye taking place in a mixed micellar medium, a differential rate method was developed for the detection of metal ions. The present kinetic spectrophotometric system has several advantages due to introduction of the mixed micelles.

Protonation of 5,10,15,20-Tetra(4-hydroxyphenyl)-porphyrin in SDS Micellar Solution

An amphiphilic porphyrin, 5, 10, 15, 20-tetra(4-hydroxyphenyl)-porphyrin (P) was solubilized in SDS micellar solutions. By taking advantage of protonation property of pyridine groups of amphiphilic porphyrin and the UV-Vis spectral sensitivity of Soret band and Q bands to the microenvironment of the porphyrin moiety, two-step protonation was studied in detail by means of UV-Vis spectroscopy. The free base, monocation and dication were described in detail in SDS micellar solution. The possibility of microphase transition was proposed to relate to the observation of two isosbestic points.

O-(β-hydroxyethyl)rutosides determination by micellar flow injection(FI)-spectrofluorimetry

A simple,eco-friendly.sensitive and economic flow injection spectrofluorimetric method was developed for the determination of O-（β-hydroxyethyl）rutosidcs.The procedure was based on the use of an anionic surfactant such as sodium dodecyl sulfate to provide an appreciable O-（β-hydroxyethyl）rutosides fluorescence enhancement,increasing considerably the sensitivity of detection.All the variables affecting the fluorescence intensity were studied and optimized.The flow rate was 5 mL/min with detection at 450 nm（after excitation at 346 nm）.A linear correlation between drug amount and peak area was established for 0-（β-hydroxyethyl）rulosides in the range of 0.01-200 μg/mL with a detection limit of0.001 μg/mL（s/n = 3）.Validation processes were performed by recovering studies with satisfactory results.The new methodology can be employed for the routine analysis of 0-（P-hydroxyethyl）rutosides in bulks as well as in commercial formulations.

Separation of Aniline Derivatives by Micellar Electrokinetic Capillary Chromatography

A micellar electrokinetic capillary chromatography (MECC) was developed for the determination of aniline and 6 substituted anilines. The seven components were separated within 25 min in the buffer solution of 40 mmol/L sodium borate and 100 mmol/L SDS. It was found that the separation was dependent on operating voltage, pH value, borate and SDS concentrations. The analytical performance was examined in terms of linear response and reproducibility. Wastewater was determined by the established method.

Effect of acidity of drugs on the prediction of human oral absorption by biopartitioning micellar chromatography

Biopartitioning micellar chromatography(BMC)is a potentially high throughput and low cost alternative for in vitro prediction of drug absorption,which can mimic the drug partitioning process in biological systems.In this paper,a data set of 56 compounds representing acidic,basic,neutral and amphoteric drugs from various structure classes with human oral absorption(HOA)data available were employed to show the effect of acidity of drugs in oral absorption prediction.HOA was reciprocally correlated to the negative value of the capacity factor(kBMC)determined by BMC at pH 7.4 and 6.5.The relationships between kBMC and the corresponding HOA values of all compounds were rather poor,but the correlations were improved when the acidity of drugs was taken into consideration.Moreover,the proposed models allowed obtaining of good predictive values for both highly and poorly absorbed compounds.It is demonstrated that the constructed models derived from compounds with the same kind of charge property are of more practically meaningful and rigorous.

Quantitative analysis of two analgesic formulations by micellar electrokinetic chromatography

A micellar electrokinetic chromatographic (MECC) method with sodium cholate as pseudostationary phase was proposed for the separation and quantitation of two analgesic formulations containing acetaminophen, dextro-methorphan hydrobromide, phenylpropanolamine hydrochloride, and chlorpheniramine maleate. The internal standard method was proved to be able to yield satisfactory results even with a modular CE instrument with RSD between 0.6 similar to 2.1%, and recoveries ranging from 98.1 similar to 99.9%.

ELECTROANALYTICAL CIIARACTERISTICS OF NICOTINIC ACID IN MICELLAR SOLUTION

The electroanalytical characteristies of nicotinic acid in miceilar solution,were studied by cyclic voltammetry,constant potential coulometry and chron ocoulometry.A procedure of the absorptive voltammetric determination of the drug was worked out.

Research on solubilization used for micellar enhanced ultrafiltration

Micellar enhanced ultrafiltration （MEUF） is a new effective treatment technology for the filtration removal of organic pollutants through solubilization. The present paper is aimed to study the solubilization of organic compounds such as chlorobenzene （CB）, pyrene and phenol by anionic, cationic and mixed anionic-nonionic surfactants such as sodium dodecyl sulfate （SDS）, cetyltrimethylammonium bromide （CTMAB） and Tween-80 （TW80） and the mixed SDS-TW80 with a batch equilibrium method. This study enables us to supply deeper investigation for MEUF. The results showed that solubilization capacity was not obvious below the critical micellar concentration （CMC）. The apparent solubilities of organic compounds were linearly related to surfactant concentrations over their CMCs. Solubilization capacity by single surfactants follow the order of TW80 〉 CTMAB 〉 SDS. The results also proved that the solubilization of the organic contaminants by the mixed surfactants can significantly be enhanced compared with the single anionic surfactant SDS. Whereas the CMC can be decreased, the solubility can be increased as long as the mass ratio of nonionic surfactant increases. The solubility enhancement efficiency of the different organic compounds follow the order of phenol 〉 CB 〉 pyrene. In addition, the solubilization ratio appears to be positively relative to the intrinsic water solubility of the organic contaminants and negatively correlates to octanol-water coefficients （Kow） of organic compounds and the hydrophile-lypophile balance values （HLB） of the surfactants.