Kinetic spectrophotometric methods for the determination of alfuzosin hydrochloride in bulk and pharmaceutical formulations

Simple and sensitive kinetic spectrophotometric methods were established for the determination of alfuzosin hydrochloride in bulk and in its pharmaceutical preparations using alkaline potassium permanganate as an oxidizing agent. The methods involve determination of alfuzosin HCl by kinetic studies of its oxidation at room temperature for a fixed time of 15 min. The absorbance of the colored manganate ions was measured at 610 nm. Alternatively, the decrease in the absorbance of permanganate upon addition of the studied drug was also measured at 525 nm. The absorbance-concentration plots in both procedures were rectilinear over the range of 2.0–30.0 μg/mL. The different experimental parameters affecting the development were carefully studied and optimized. The determination of alfuzosin HCl by the fixed concentration and initial rate methods is also feasible with the calibration equations obtained but the fixed time method has been found to be more applicable. Both procedures were applied to the determination of alfuzosin HCl in formulations. The results obtained were in good agreement with those obtained using reference methods.     

Flexible microfluidic cloth-based analytical devices using a low-cost wax patterning technique

This paper describes the fabrication of microfluidic cloth-based analytical devices (μCADs) using a simple wax patterning method on cotton cloth for performing colorimetric bioassays. Commercial cotton cloth fabric is proposed as a new inexpensive, lightweight, and flexible platform for fabricating two- (2D) and three-dimensional (3D) microfluidic systems. We demonstrated that the wicking property of the cotton microfluidic channel can be improved by scouring in soda ash (Na(2)CO(3)) solution which will remove the natural surface wax and expose the underlying texture of the cellulose fiber. After this treatment, we fabricated narrow hydrophilic channels with hydrophobic barriers made from patterned wax to define the 2D microfluidic devices. The designed pattern is carved on wax-impregnated paper, and subsequently transferred to attached cotton cloth by heat treatment. To further obtain 3D microfluidic devices having multiple layers of pattern, a single layer of wax patterned cloth can be folded along a predefined folding line and subsequently pressed using mechanical force. All the fabrication steps are simple and low cost since no special equipment is required. Diagnostic application of cloth-based devices is shown by the development of simple devices that wick and distribute microvolumes of simulated body fluids along the hydrophilic channels into reaction zones to react with analytical reagents. Colorimetric detection of bovine serum albumin (BSA) in artificial urine is carried out by direct visual observation of bromophenol blue (BPB) colour change in the reaction zones. Finally, we show the flexibility of the novel microfluidic platform by conducting a similar reaction in a bent pinned μCAD.     

Green Synthesized ZnO Nanoparticles as Biodiesel Blends and Their Effect on the Performance and Emission of Greenhouse Gases

Pollution and global warming are a few of the many reasons for environmental problems, due to industrial wastes and greenhouse gases, hence there are efforts to bring down such emissions to reduce pollution and combat global warming. In the present study, zinc oxide nanoparticles are green synthesized using cow dung as fuel, through combustion. Synthesized material was characterized by FTIR, XRD, UV, and FESEM. The as-prepared ZnO-GS NPs were employed as a transesterification catalyst for the preparation of biodiesel from discarded cooking oil. The biodiesel obtained is termed D-COME (discarded cooking oil methyl ester), which is blended with 20% commercial diesel (B20). Additionally, this blend, i.e., B20, is further blended with varying amounts of as-prepared ZnO-GS NPs, in order to ascertain its effects on the quality of emissions of various greenhouse gases such as hydrocarbons, CO_x, NO_x. Moreover, the brake thermal efficiency (BTHE) and brake specific fuel consumption (BSFC) were studied for their blends. The blend (B20) with 30 mg of ZnO-GS, i.e., B20-30, displays the best performance and reduced emissions. Comparative studies revealed that the ZnO-GS NPs are as efficient as the ZnO-C NPs, indicating that the green synthetic approach employed does not affect the efficiency of the ZnO NPs.     

Modular synthesis of unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene molecular semiconductors for organic transistors

A modular approach to underexplored, unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene (BTBT) scaffolds delivers a library of BTBT materials from readily available coupling partners by combining a transition-metal free Pummerer CH–CH-type cross-coupling and a Newman–Kwart reaction. This effective approach to unsymmetrical BTBT materials has allowed their properties to be studied. In particular, tuning the functional groups on the BTBT scaffold allows the solid-state assembly and molecular orbital energy levels to be modulated. Investigation of the charge transport properties of BTBT-containing small-molecule:polymer blends revealed the importance of molecular ordering during phase segregation and matching the highest occupied molecular orbital energy level with that of the semiconducting polymer binder, polyindacenodithiophene-benzothiadiazole (PIDTBT). The hole mobilities extracted from transistors fabricated using blends of PIDTBT with phenyl or methoxy functionalized unsymmetrical BTBTs were double those measured for devices fabricated using pristine PIDTBT. This study underscores the value of the synthetic methodology in providing a platform from which to study structure–property relationships in an underrepresented family of unsymmetrical BTBT molecular semiconductors.

A modular approach to underexplored, unsymmetrical [1]benzothieno[3,2-b][1]benzothiophene (BTBT) scaffolds, combining a transition-metal free Pummerer CH–CH-type cross-coupling and a Newman–Kwart reaction, delivers a library of BTBT materials.     

Insights on Cryogenic Distillation Technology for Simultaneous CO2 and H2S Removal for Sour Gas Fields

Natural gas demand has dramatically increased due to the emerging growth of the world economy and industry. Presently, CO₂ and H₂S content in gas fields accounts for up to 90% and 15%, respectively. Apart from fulfilling the market demand, CO₂ and H₂S removal from natural gas is critical due to their corrosive natures, the low heating value of natural gas and the greenhouse gas effect. To date, several gas fields have remained unexplored due to limited technologies to monetize the highly sour natural gas. A variety of conventional technologies have been implemented to purify natural gas such as absorption, adsorption and membrane and cryogenic separation. The application of these technologies in natural gas upgrading are also presented. Among these commercial technologies, cryogenic technology has advanced rapidly in gas separation and proven ideally suitable for bulk CO₂ removal due to its independence from absorbents or adsorbents, which require a larger footprint, weight and energy. Present work comprehensively reviews the mechanisms and potential of the advanced nonconventional cryogenic separation technologies for processing of natural gas streams with high CO₂ and H₂S content. Moreover, the prospects of emerging cryogenic technologies for future commercialization exploitation are highlighted.     

<em>In Vitro</em> Anti-diabetic Activities and Chemical Analysis of Polypeptide-k and Oil Isolated from Seeds of <em>Momordica charantia</em> (Bitter Gourd)

The amino acid and fatty acid composition of polypeptide k and oil isolated from the seeds of Momordica charantia was analysed. The analysis revealed polypeptide k contained 9 out of 11 essential amino acids, among a total of 18 types of amino acids. Glutamic acid, aspartic acid, arginine and glycine were the most abundant (17.08%, 9.71%, 9.50% and 8.90% of total amino acids, respectively). Fatty acid analysis showed unusually high amounts of C18-0 (stearic acid, 62.31% of total fatty acid). C18-1 (oleic acid) and C18-2 (linoleic acid) were the other major fatty acid detected (12.53% and 10.40%, respectively). The oil was devoid of the short fatty acids (C4-0 to C8-0). Polypeptide k and oil were also subjected to in vitro α-glucosidase and α-amylase inhibition assays. Both polypeptide k and seed oil showed potent inhibition of α-glucosidase enzyme (79.18% and 53.55% inhibition, respectively). α-Amylase was inhibited by 35.58% and 38.02%, respectively. Collectively, the in vitro assay strongly suggests that both polypeptide k and seed oil from Momordica charantia are potent potential hypoglycemic agents.