Surfactant Media Research Articles

Catalytic effect of the in-situ rhodium(III) complexes in surfactant medium on the auto-oxidation of 1,2-hydroxyphenylthiourea: A theoretical and experimental study for rhodium(III) sensing

1,2-hydroxyphenylthiourea(HPTU) undergoes auto-oxidation to form an yellow colored dimer. The process of auto-oxidation is enhanced by the presence of trace quantities of transition metal ions and transition metal complexes that act as catalysts. In the current study, catalytic potential of rhodium(III) complexes on the auto-oxidation of 1,2-hydroxyphenylthiourea(HPTU) was studied theoretically using quantum mechanical calculations and experiments were carried out using photometry and fluorometry. DFT studies inferred that [Rh(Py)6]Cl3 showed a better catalytic activity in the dimerization of HPTU. Theoretical studies were subsequently validated through experiments using photometric methods and the range of detection was determined to be 6 ng/mL–100 ng/mL. The detection limit was observed to be 2 ng/mL. Analytical parameters such as pH, reagent concentration, metal ion concentration, appropriate activators and surfactants were established.

Proniosomes Nanoparticle for the Treatment of Peripheral Arterial Disease.

The common symptom of systemic atherosclerosis is peripheral arterial disease (PAD), which occurs when the artery lumen in the lower extremities gradually becomes blocked by atherosclerotic plaque. The most frequent symptom of lower extremity PAD, called "vascular claudication," which is pain experienced when walking. Partial or total blockage of the peripheral arteries in the upper and lower limbs is called PAD. The danger of death from concurrent coronary artery and cerebrovascular atherosclerosis outweighs the risk of amputation. However, niosomes have issues with fusion, aggregation, leakage, vesicle sedimentation, and difficulty in sterilizing. A more recent strategy known as pro-vesicular carriers was used to solve these issues. The formulations in Proniosomes are dry and anhydrous, protected with a non-ionic surfactant that serves as a carrier when combined with water. Formulation prepared by organic solvent, surfactant, cholesterol, other components and hydration medium. Coacervation Phase separation Technique used for proniosome Nanoparticle. Box Bhenken Design is used for optimization batches. In this context, we shall discuss the development of Proniosome for the treatment of peripheral arterial diseases. From here, we know that proniosome nanoparticles is pro vesicular system good characteristics and effectiveness for treating peripheral arterial diseases. Proniosomes may be created using various techniques, which may impact how they develop along with the drug's characteristics. They increase the drug's stability while being delivered while being entrapped. They don't need particular conditions for handling, protection, storage, or industrial manufacturing.

Application of Quality by Design in the Development of Hydrogen Sulfide Donor Loaded Polymeric Microparticles

Hydrogen sulfide (H2S) is a multifaceted gasotransmitter molecule which has potential applications in many pathological conditions including in lowering intraocular pressure and providing retinal neuroprotection. However, its unique physicochemical properties pose several challenges for developing its efficient and safe delivery method system. This study aims to overcome challenges related to H2S toxicity, gaseous nature, and narrow therapeutic concentrations range by developing polymeric microparticles to sustain the release of H2S for an extended period. Various formulation parameters and their interactions are quantitatively identified using Quality-by-Design (QbD) approach to optimize the microparticle-based H2S donor (HSD) delivery system. Microparticles were prepared using a solvent-evaporation coacervation process by using polycaprolactone (PCL), soy lecithin, dichloromethane, Na2S.9H2O, and silicone oil as polymer, surfactant, solvent, HSD, and dispersion medium, respectively. The microparticles were characterized for size, size distribution, entrapment efficiency, and H2S release profile. A Main Effects Screening (MES) and a Response Surface Design (RSD) model-based Box-Behnken Design (BBD) was developed to establish the relationship between critical process parameters (CPPs) and critical quality attributes (CQAs) qualitatively and quantitatively. The MES model identified polymer to drug ratio and dispersion medium quantity as significant CPPs among others, while the RSD model established their quantitative relationship. Finally, the target product performance was validated by comparing predicted and experimental outcomes. The QbD approach helped in achieving overall desired microparticle characteristics with fewer trials and provided a mathematical relationship between the CPPs and the CQAs useful for further manipulation and optimization of release profile up to at least 30 days.Graphical

Interfacial and surface adsorption phenomenon in the dissolution behavior of 8-hydroxy quinoline

The solubilization and dissolution behavior of 8-hydroxyquinoline was studied in surfactant medium. Anionic surfactant - Sodium dodecyl sulphate (SDS), cationic surfactant - cetyltrimethylammonium bromide (CTAB), non-ionic surfactant - Triton X-100 were put to use while performing the work. Meaningful interaction of surfactant with cationic and anionic surfactants were only observed. In either of the surfactant medium, the solubility vs surfactant concentration profile has shown a maximum at around the concentration of the surfactant at which the micellization of the surfactant has begun i.e., cmc or critical micelle concentration was reached. In CTAB medium, the solubility of 8-hydroxyquinoline has shown double maxima, one of which was in the post-micellar region. The acid dissociation constant, binding constant of 8-hydroxyquinoline, Gibb’s free energy of solubilization and the partition coefficient (molar) between the aqueous and micellar aggregate phases were computed. Based on all the observations suitable explanations are extended. From the experimental results, the micelle-(8-HQ) binding constant, partition coefficient and free energy of solubilization was computed to supplement the assertions made.

Ru(III)-Catalyzed L-Glutamic Acid Oxidation by Hexacyanoferrate(III) in an Anionic Surfactant Medium: A Kinetic and Mechanistic Approach

Ru(III)-Catalyzed L-Glutamic Acid Oxidation by Hexacyanoferrate(III) in an Anionic Surfactant Medium: A Kinetic and Mechanistic Approach

Dispersion control by using a bulky surfactant medium in the LB films for the enhancement of linearly polarized luminescence of Eu complexes

Abstract The ff transition of lanthanide ions such as Eu in the complex appears as unique energy relaxation process as luminescence after the intramolecular energy transfer from the photo-excitation of the ligand with π-electronic system. The Langmuir-Blodgett (LB) film consisting of Eu and amphiphilic naphtoic acids (NaphC15) induced the linearly polarized luminescence (LPL) with a medium, stearic acid (SA), to isolate the luminescence component by the layer structure and to keep the softness at the monolayer depositions on the quartz substrate as reported previously. Here, we used a bulky medium, 3-methyl-4-penthadecyl benzoic acid (MPBA), instead of SA, and found the Eu-NaphC15 in the LB film places more independently resulting in the 4-fold high quantum yields compared with previous system. The structures of LB films of Eu-NaphC15 with MPBA were elucidated by the measurement of synchrotron XRD and XPS. Various electronic spectra were quantitatively observed to discuss the effect molecular aggregation through much/less ππ-interaction of NaphC15 for the intensified LPL in the films.

Kinetic study of Ru(III) – catalyzed oxidation of L-phenylalanine by hexacyanoferrate(III) in an anionic surfactant medium

Abstract The kinetic investigation of Ru(III) promoted oxidation of L-phenylalanine (L-PheAla) by [Fe(CN)6]3− has been performed in anionic sodium dodecyl sulfate (SDS) micellar medium by recording the decrease in absorbance at 420 nm corresponding to [Fe(CN)6]3− using an UV–visible spectrophotometer. Using the pseudo-first-order condition, the course of the reaction was studied as a function of [Fe(CN)6 3−], ionic strength, [OH−], [SDS], [Ru3+], [L-PheAla] and temperature by changing one variable at a time. The results exhibit that [OH−], [SDS], and [L-PheAla] are the crucial parameters that have an appreciable influence on the reaction rate. The reaction exhibits first-order kinetics in concentration ranges of Ru(III), [Fe(CN)6]3− and at low [L-PheAla] and [OH−] concentrations. The incremental trend observed in the reaction rate with electrolyte concentration shows a positive salt effect. The reaction rate is almost 10 times faster in SDS micellar medium than in aqueous medium. [Fe(CN)6]3− has no appreciable effect on the CMC of SDS, since the polar head of SDS and [Fe(CN)6]3− are both negatively charged. The K+ obtained from K3[Fe(CN)6] and KNO3 decreases the repulsion between the negatively charged heads of the surfactant molecules, which decreases the CMC of SDS. The activation parameters also support the outer-sphere electron transfer mechanism.

Semi-empirical calculations and potentiometric studies on complexation equilibria of 2,2’-Bipyridyl in SDS and TBAB micellar media

Chemical speciation of Cu(II) complexes of 2,2-Bipyridyl in the of the presence of different- surfactant media (TBAB and SDS) has been studied pH metrically. The models containing different kinds of species were refined using the computer program, MINIQUAD75 and formation constants were determined. The predominant species detected were Cu(bipyH) and Cu(bipy)2 in both surfactant media. It was found that the formation constant is more in SDS compared to TBAB and aqueous media because the proton association is more in the anionic micellar medium. Binding energies and HOMO-LUMO energy gaps were calculated from semi-empirical studies based on PM6 method. It was found that Cu(bipy)2 is more stable than Cu(bipy) and Cu(bipyH+).

Kinetic Study of Hg(II)-Promoted Cyanide Substitution from Hexacyanoferrate(II) in an Anionic Surfactant Medium by N-R-Salt

Kinetic Study of Hg(II)-Promoted Cyanide Substitution from Hexacyanoferrate(II) in an Anionic Surfactant Medium by N-R-Salt

Electroanalytical Investigation of Cancer Chemotherapy Drug Vinorelbine On Disposable Pencil Graphite Electrode in Surfactant Media by Voltametric Method

One of the biggest global public health issues, cancer has a negative impact on people's health and quality of life. Therefore, it is undeniable that the interest in drugs for cancer treatment has increased. On the other hand, in addition to patient safety during the administration of drugs used in cancer treatment due to their possible toxic properties, it is crucial to maintain a safe working environment and to safeguard the health professionals who provide the treatment from the possibility of coming into touch with this class of medications. At the same time, it is extremely important to develop methods for the analysis of antineoplastic drugs in different environments.
 In this study, a new application of disposable pencil-tip graphite electrode for the determination of Vinorelbine, which is one of the semi-synthetic derivatives of Vinca alkaloids, which is in the class of herbal antineoplastic drugs used in cancer treatment, is presented.
 Using a pencil-tip graphite electrode, the CV and SWV techniques were used to examine the electrochemical characteristics of vinorelbine throughout a large pH range (2.0-12.0), both without and with surfactant medium. Vinorelbine in BR (pH=10.0) buffer containing 3 mM cationic surfactant (tetra-n-butylammonium bromide) by SW-AdSV technique, it responded voltammetrically with a potential of +0.75 V. The suggested technique has been used successfully with human urine samples that have been spiked with vinorelbine and medication formulations.

Investigation of the electrochemical properties of vinblastine on boron-doped diamond electrode treated with anodic pre-treatment in anionic surfactant medium

Investigation of the electrochemical properties of vinblastine on boron-doped diamond electrode treated with anodic pre-treatment in anionic surfactant medium

Using a Boron‐Doped Diamond Electrode in Anionic Surfactant Media as an Improved Electrochemical Sensor for the Anticancer Drug Ibrutinib

AbstractThe electrochemical properties of ibrutinib (IBR), a new generation smart anti‐cancer drug, one of the Bruton's tyrosine kinase (BTK) inhibitors were investigated by a voltammetric method in the anionic surfactant (sodium dodecyl sulfate, SDS) medium with the boron‐doped diamond electrode (BDDE). IBR showed an oxidation step at about +1.56 V (vs Ag/AgCl (3.0 mol L−1 KCl) by cyclic voltammetry (CV) technique in 0.1 mol L−1 H2SO4 solution. IBR was found to be irreversible and diffusion‐controlled on the surface of the BDDE with studies of scan rate. The possible electrochemical oxidation reaction of IBR with the electroactive ring (pyrazole‐pyrimidine ring) in the structure of IBR is discussed. Square wave voltammetry (SWV) was preferred as the study method due to reproducibility for the determination of IBR in pharmaceutical and urine samples. At optimal values of SWV parameters, IBR showed good linearity in the concentration range of 0.01–2.00 μg mL−1 (5.7×10−8–2.3×10−6 mol L−1) in 0.1 mol L−1 H2SO4 with 6×10−4 M SDS. The detection (LOD) and quantification (LOQ) limits for IBR were set at 0.003 μg mL−1 (6.9×10−9 mol L−1) and 0.01 μg mL−1 (2.27×10−8 mol L−1), respectively. The relative standard deviation of the intra‐day and inter‐day repeatability of the proposed method was found 2.15 and 3.76, respectively. The necessary validation parameters have also been studied, and the recovery results obtained from both pharmaceutical dosage form and human urine samples show that the developed method is accurate and precise.

Kinetic Study of Ru(III) Promoted Oxidation of L-Tryptophan in an Anionic Surfactant Medium by Hexacyanoferrate(III)

The kinetic investigation of Ru(III) promoted oxidation of L-tryptophan (Trp) by [Fe(CN)6]3- has been performed in anionic sodium dodecyl sulfate (SDS) micellar medium by recording the decrease in absorbance at 420 nm, corresponding to [Fe(CN)6]3- using UV-visible spectrophotometer. Pseudo-first-order condition has been used to examine the progress of reaction as a function of [Fe(CN)63−], ionic strength, [OH-], [SDS], [Ru3+], [Trp], and temperature by changing one variable at a time. The results exhibit that [OH-], [SDS], and [Trp] are the decisive parameter showing an appreciable effect on reaction rate. The reaction exhibits first-order kinetics in the studies concentration range of Ru(III), [Fe(CN)6]3− and at lower [Trp] and [OH-]. The incremental trend observed in the reaction rate with electrolyte concentration shows a positive salt effect. The reaction rate is almost ten times faster in SDS micellar medium compared to the aqueous medium. [Fe(CN)6]3- does not show any appreciable effect on the critical micellar concentration (CMC) of SDS as the polar head of SDS and [Fe(CN)6]3- both are negatively charged. The K+ obtained from K3[Fe(CN)6] and KNO3 decreases the repulsion between the negatively charged heads of the surfactant molecules thereby decreasing the CMC of SDS. The activation parameters also support the outer-sphere electron transfer mechanism as proposed by us. Resumen. El estudio cinético de la oxidación de L-tryptofano (Trp) con [Fe(CN)6]3- asistida por Ru(III), se llevó a cabo en un medio micelar de dodecilsulfato de sodio aniónico (SDS) y se monitoreó utilizando espectrometría de UV-visible midiendo la disminución de la absorbancia a 420 nm, correspondiente al [Fe(CN)6]3-. Para examinar el avance de la reaccción se utilizaron condiciones de pseudo-primer orden en función de [Fe(CN)63−], fuerza iónica, [OH-], [SDS], [Ru3+], [Trp], y temperatura, variando siempre una sola una variable. Los resultados indican, que los parametros decisivos que tuvieron un efecto apreciable sobre la velocidad de la reacción son [OH-], [SDS], y [Trp]. La reacción sigue una cinética de primer orden en el rango de concentraciones de estudio de Ru(III), [Fe(CN)6]3− y a bajas concentraciones de [Trp] y [OH-]. La tendencia de incremento de velocidad de la reacción con aumento de la concentración del electrolito muestra un efecto salino positivo. La velocidad de la reacción en el medio micelar de SDS es casi diez veces mayor que en solución acuosa. [Fe(CN)6]3- no muestra ningún efecto appreciable en la concentración crítica micelar (CMC) de SDS debido a que el grupo polar del SDS (SO3-, cabeza) y el [Fe(CN)6]3- tienen ambos carga negativa. Los cationes K+ provenientes del K3[Fe(CN)6] y KNO3 disminuyen la repulsión entre las cabezas con cargas negativas del surfactante, bajando así la CMC del SDS. Los parámetros de activación apoyan también el mecanismo de transferencia de electrones de la esfera exterior propuesto.

Surfactant catalyzed electron transfer mechanism in the oxidation of racemic tartaric acid by Ce(IV)

Oxidation of α-hydroxy acid, racemic tartaric acid and its kinetic studies have been carried out to establish the mechanism of oxidation. The electron transfer reaction was performed in presence of surface active agents, surfactants, a clean and green catalytic material, using Ce(IV) as the oxidant. The progress of the reaction was monitored using a spectrophotometer by recording the fall in absorbance of Ce(IV) at its λ max (wave length of maximum absorbance) of 380 nm. Disappearance of Ce(IV) is observed to be first order at constant [H + ]. Plot of log(Absorbance) against time is found to be linear in the initial stages of the reaction. The results of oxidation rates show a complex dependence of rate on [H + ]. The pseudo first order rate constants ( k ) obtained with varying substrate concentration and the plot of k obs /[substrate] vs [substrate] are observed to be excellently linear with positive slope. Plots of pseudo first order rate constants in presence of surfactant (sodium dodecyl sulphate, SDS) against the [SDS] abruptly rises in the concentration range below cmc (critical micelle concentration) after which the rate exponentially falls. Based on all the findings, Berezin model has been advanced to explain the observed kinetic phenomenon in the surfactant medium.

Effect of Cationic Surfactant in the Synthesis Process of Nano γ-Alumina for Petroleum Industry Application

Nanotechnology is widely used in industries, including catalyst synthesis for oil and gas industries to enhance and perform new Characteristics of materials. Cetyl tri methyl ammonium bromide (CTAB) cationic surfactant was used in the synthesis of spherical nanostructured γ-alumina to enhance the morphology of the prepared nano gamma alumina which is used as a catalyst support in the naphtha reforming process. The preparation was carried out by co-precipitation method by adding drop wise of ammonium hydroxide solution and aluminum nitrate nonahydrate solution simultaneously to a solution of surfactant medium, PH and temperature of reaction were kept at 8 and 30 cᵒ respectively. The gamma alumina obtained were characterized by X- Ray Diffraction (XRD), nitrogen adsorption-desorption analysis (ASAP 2020, Micromeretics) and atomic force microscope (AFM). The sample of synthesized gamma alumina with the CTAB cationic surfactant showed that surface are (314 m2/g), pore volume (0.37 cm3/g), and pore size (3.6 nm).

Application of boron-doped diamond electrode for rapid and sensitive voltammetric detection of vildagliptin in anionic surfactant medium

Application of boron-doped diamond electrode for rapid and sensitive voltammetric detection of vildagliptin in anionic surfactant medium

Humic acid-mediated reduction in toxicity of Co3O4 NPs towards freshwater and marine microalgae in surfactant mixed medium.

The ever-increasing applications of Co3O4 nanoparticles (NPs) have posed a serious concern about their discharge in the aquatic environment and ecotoxic implications. Being toxic towards aquatic species, the impact of other aquatic components such as dissolved organic matter (DOM), salinity, and surfactants are not studied sufficiently for their effect on the stability and ecotoxicity of Co3O4 NPs. The present study aims at the influence of humic acid (HA) on the toxicity of Co3O4 NPs in freshwater (C. minutissima) and marine (T. suecica) microalgae under surfactants mixed medium. The measure of % reduction in biomass and photosynthetic pigment were used as toxicity endpoints. Among various tested concentrations of HA, 25mg/L HA was found suitable to minimize the NP's toxicity with or without the presence of surfactants. Co3O4 NPs mediated reduction in biomass of C. minutissima was significantly minimized by the cumulative effect of HA with T80 (51.68 ± 4.55%) followed by CTAB (46.23 ± 5.62%) and SDS (42.60 ± 2.46%). Similarly, HA with T80 (26.93 ± 6.38%) followed by SDS (17.02 ± 6.64%) and CTAB (13.01 ± 3.81%) were found to minimize the growth inhibitory effect of Co3O4 NPs in T. suecica. The estimation of chlorophyll - a content also indicated that microalgae treated with HA could maintain their photosynthetic ability more than control even in the co-presence of surfactants. Also, the reduced toxicity of Co3O4 NPs were attributed to an increase in hydrodynamic sizes of HA-treated Co3O4 NPs in both marine media (f/2) and freshwater media (BG11) due to increased aggregation and faster sedimentation of Co3O4 NPs.

The Effect of Anionic Surfactant and Stripping Voltammetry on the Signal of Ibrutinib at Nano-Level

Ibrutinib is a selective inhibitor of Bruton’s tyrosine kinase, which is used in chronic lymphocytic leukaemia treatment. In this study, an adsorptive stripping square wave voltammetry was developed to quantify the nanomolar level of ibrutinib in an anionic surfactant medium. The effect of supporting electrolyte, pH, surfactant concentration, and scan rate on the voltammetric peak current and potential of ibrutinib were evaluated using a glassy carbon electrode. The possible electrochemical mechanism was discussed with model compounds. The electrochemical behaviour of ibrutinib shows irreversible and diffusion-adsorption mixed controlled oxidation processes depending on scan rate studies in 0.1 M sulphuric acid. The sensitivity of the method was increased by the combined use of surfactant and stripping conditions. Under optimum conditions, a concentration range of 4.00 × 10−9 to 2.00 × 10−7 M was linear in 0.1 M sulphuric acid, including 2.00 × 10−3 M sodium lauryl sulphate. The limit of detection was calculated as 2.73 × 10−10 M. The proposed method was applied for the quantification of ibrutinib in biological samples. In addition, this method was evaluated in the presence of some potential interference substances.

Kinetic study of Hg(II)‐promoted substitution of cyanide from hexacyanoferrate(II) in an anionic surfactant medium by 2,2′‐bipyridine

AbstractThe kinetic investigation of Hg(II)‐promoted reaction between [Fe(CN)6]4− and 2,2′‐bipyridine (Bipy) has been performed in anionic sodium dodecyl sulfate (SDS) micellar medium by recording the surge in absorbance at 400 nm, corresponding to ultimate reaction product [Fe(CN)4 Bipy]2− using UV–visible spectrophotometer. Pseudo‐first‐order condition has been used to examine the progress of reaction as a function of temperature, [Fe(CN)64−], ionic strength, [SDS], pH, [Hg2+], and [Bipy] by changing one parameter at a time. The results exhibit that [Hg2+], [SDS], and pH are the decisive parameter showing maximum reaction rate at 1.5 × 10−4 mol dm−3, 6.0 × 10−3 mol dm−3, and 3.8, respectively. [Fe(CN)6]4− does not show any appreciable effect on the critical micellar concentration (CMC) of SDS as the polar head of SDS and [Fe(CN)6]4− both are negatively charged. Variable order kinetics was observed for [Fe(CN)6]4− and Bipy in their examined concentration range. The reverse response observed in the reaction rate with [KNO3] shows a negative salt effect. The K+ provided by K4[Fe(CN)6] and KNO3 decreases the repulsion between the negatively charged heads of the surfactant molecules thereby decreasing the CMC of SDS. The negative value for the entropy of activation also supports the interchange dissociative (Id) mechanism recommended by us.

Comparison of a single pharmaceutical surfactant versus intestinal biorelevant media for etravirine dissolution: Role and impact of micelle diffusivity

Etravirine is an antiviral whose oral absorption is limited by low solubility/dissolution. The objective was to predict and compare etravirine’s surfactant-mediated dissolution into polyoxyethylene-10 lauryl ether (POE) and FeSSIF-V2, including the contribution of slow micelle diffusivity. Dynamic light scattering (DLS) was used to measure the size and diffusivity values of drug-loaded micelles. In vitro intrinsic dissolution into surfactant media were predicted using a model for surfactant-mediated dissolution. Compared to maleic buffer, POE and FeSSIF-V2 increased etravirine solubility 232-fold and 8.97-fold, respectively. From DLS, micelle diffusivity of drug-loaded POE micelle and FeSSIF-V2 mixed-micelle was 5.15x10−7 cm2/s and 5.76x10−8 cm2/s, respectively. Observed and predicted dissolution enhancement into POE were 50.7 and 31.3, and 1.26 and 1.24 into FeSSIF-V2, respectively. Hence, there was high dissolution enhancement into POE, although the observed enhancement was only 21.9% of the observed solubility enhancement, reflecting the attenuating impact of the large and slowly diffusing drug-loaded POE micelles. Meanwhile, there was minimal dissolution enhancement into FeSSIF-V2, and the observed enhancement was only 14.0% of the observed solubility enhancement, reflecting the even slower diffusing drug-loaded FeSSIF-V2 mixed-micelles compared to drug-loaded POE micelles. Results are considered in light of designing a single pharmaceutical surfactant system for dissolution that mimics a FeSSIF-V2 system.