Reversed flow-injection method for estimation of chlorpromazine in pharmaceuticals and urine samples using charge-transfer complexation

A simple, automated and sensitive reversed flow-injection analysis (rFIA) method for the determination of chlorpromazine hydrochloride (CLP) in pharmaceutical formulations and human urine samples is described. The automated method is based on the formation of charge-transfer complex between CLP (donor) with new reagent (an acceptor) used for the first time namely, 4,4’-tetramethyl-diaminodiphenylmethane (TDM) in the presence of K2S2O8 as an oxidant. An intense blue-colored product, which gave a maximum absorbance at 604 nm, was formed immediately at room temperature. The various chemical and physical conditions that affected the reaction have been studied. The calibration curve was rectilinear within the concentration range 1-45 µg/mL and the detection and quantification limits of 0.72 and 2.40 µg/mL respectively with a sample through put of 80 sample/hour. The proposed procedure was applied successfully for the estimation of CLP and the results obtained were favorably compared with those given by a reference method, and there was no significant difference between the obtained results, regarding accuracy and precision at the 95% confidence level.               KEY WORDS: Chlorpromazine, Flow injection analysis, Charge-transfer complexation Bull. Chem. Soc. Ethiop. 2019, 33(1), 11-20.DOI: https://dx.doi.org/10.4314/bcse.v33i1.

Mechanical properties study of pseudo-stem banana fiber reinforced epoxy composite

The source of banana fiber is the waste banana trunks or stems which are abundant in many places in the world. Therefore, composites of high–strength pseudo-stem banana woven fabric reinforcement polymer can be used in a broad range of applications. The objective of this paper is to study the tensile, flexural, and impact properties of pseudostem banana fiber reinforced epoxy composites

Utility of Certain Nucleophilic Aromatic Substitution Reactions for the Assay of Ethamsylate in its Dosage forms and in Presence of its Degradation Product

The study represents the first report on the development of spectrophotometric methods for determination of ethamsylate (EST) in the presence of hydroquinone as an impurity and/or acidic degradation product. The proposed methods are based on the reaction of EST through it,s secondary amino group either with 1,2-naphthoquinone-4-sulphonate sodium (NQS) at pH 10.7 or 2,4-dinitrofluorobenzene (DNFB) at pH 9.3 to form orange and yellow colored reaction products peaking at 478 and 387 nm for methods (I) and (II), respectively. The different experimental parameters affecting the development and stability of the reaction products in methods (I) and (II) were carefully studied and optimized. The absorbance-concentration plots were rectilinear over the concentration ranges of 2-30 and 2-14 µg mL−1 for methods (I) and (II), respectively. The lower detection limits were 0.13 and 0.19 µg mL−1 and the lower quantitation limits were 0.44 and 0.63 µg mL−1 for methods (I) and (II), respectively. Both methods were successfully applied to commercial ampoules and tablets

Spectrophotometric determination of the sulfhydryl containing drug mesna

AbstractFour simple and sensitive spectrophotometric methods were developed for the determination of the sulfhydryl containing drug mesna (MSN). Methods I and II rely on nucleophilic aromatic substitution reactions using two UV tagging reagents namely: 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) for method I and 2,4-dinitrofluorobenzene (DNFB) for method II. Both reactions took place in alkaline buffered medium and the obtained yellowish products were measured at 414 and 332nm for methods I and II, respectively. Methods III and IV are indirect spectrophotometric methods based on the suppressive effect of MSN on the absorption of two ternary complex systems which are composed of 1,10-phenanthroline, silver and eosin for method III and 1,10-phenanthroline, silver and bromopyrogallol red for method IV. The decrease in absorbance of the ternary complexes was measured at 547 and 635nm for methods III and IV, respectively. All the experimental parameters affecting these reactions were carefully studied and optimized. The methods were validated as per the ICH guidelines. The methods were applicable in the linearity ranges 4–18μg/mL for method I, 4–16μg/mL for method II, 0.25–2.25μg/mL for method III and 0.25–1.75μg/mL for method IV. The proposed methods were successfully applied for the analysis of MSN in its commercial ampoules and no interference was encountered from the present excipients as indicated by the satisfactory percentage recoveries. The results obtained were in a good agreement with those obtained from a previously published method of the investigated drug

High Performance Liquid Chromatographic Assay for the Simultaneous Determination of Posaconazole and Vincristine in Rat Plasma

Purpose. Developing a validated HPLC-DAD method for simultaneous determination of posaconazole (PSZ) and vincristine (VCR) in rat plasma. Methods. PSZ, VCR, and itraconazole (ITZ) were extracted from 200 μL plasma using diethyl ether in the presence of 0.1 M sodium hydroxide solution. The organic layer was evaporated in vacuo and dried residue was reconstituted and injected through HC-C18 (4.6 × 250 mm, 5 μm) column. In the mobile phase, acetonitrile and 0.015 M potassium dihydrogen orthophosphate (30 : 70 to 80 : 20, linear gradient over 7 minutes) pumped at 1.5 mL/min. VCR and PSZ were measured at 220 and 262 nm, respectively. Two Sprague Dawley rats were orally dosed PSZ followed by iv dosing of VCR and serial blood sampling was performed. Results. VCR, PSZ, and ITZ were successfully separated within 11 min. Calibration curves were linear over the range of 50–5000 ng/mL for both drugs. The CV% and % error of the mean were ≤18% and limit of quantitation was 50 ng/mL for both drugs. Rat plasma concentrations of PSZ and VCR were simultaneously measured up to 72 h and their calculated pharmacokinetics parameters were comparable to the literature. Conclusion. The assay was validated as per ICH guidelines and is appropriate for pharmacokinetics drug-drug interaction studies

Theoretical analysis of triple-pass erbium-doped fiber amplifier

Many configurations of EDFA producing triple pass EDFAs have been used, however, only two configurations are commonly used in the optical fiber communication system due to their high performance. Those two configurations are configured in a double stage EDFA. The first configuration is (configuration A) consists of a single-pass EDFA as the first stage and a double-pass EDFA as the second stage. The second configuration is (Configuration B) which consists of a double-pass EDFA as the first stage and a single-pass EDFA as the second stage. The Literature shows the use of triple pass EDFA is either with configuration A or configuration B and literature also shows there is no theoretical analysis and comparison between the performance of two Triple-pass EDFA configurations A and B. This paper focus on the performance analysis of both configurations A and B. The importantance of this research is the theoretical analyses that analyze the performance of those two configurations and illustrate a comparison between them. This comparison is important to show which of the two configurations is more reliable in amplifying optical signal for the fiber optic communication systems

Solving Competitive Traveling Salesman Problem Using Gray Wolf Optimization Algorithm

In this paper a Gray Wolf Optimization (GWO) algorithm is presented to solve the Competitive Traveling Salesman Problem (CTSP). In CTSP, there are numbers of non-cooperative salesmen their goal is visiting a larger possible number of cities with lowest cost and most gained benefit. Each salesman will get a benefit when he visits unvisited city before all other salesmen. Two approaches have been used in this paper, the first one called static approach, it is mean evenly divides the cities among salesmen. The second approach is called parallel at which all cities are available to all salesmen and each salesman tries to visit as much as possible of the unvisited cities. The algorithms are executed for 1000 times and the results prove that the GWO is very efficient giving an indication of the superiority of GWO in solving CTSP