scholarly journals SPECTROPHOTOMETRIC DETERMINATION OF SOME PHARMACEUTICAL COMPOUNDS USING 2,2-DIPHENYL-1-PICRYLHYDRAZYL

2000 ◽  
Vol 68 (4) ◽  
pp. 403-419 ◽  
Author(s):  
Hesham Salem

A simple, rapid and sensitive spectrophotometric procedure for the assay of some drugs has been developed. The method is based on the reaction of the studied drugs with 2,2-diphenyl-1-picrylhydrazyl (DPPH). The latter is employed to abstract a hydrogen atom from the drugs thereby promoting a process of radical coupling. This results in a reduction of the violet color of DPPH with the formation of the yellow colored 2,2-diphenyl-1-picrylhydrazine (DPPH2). The decrease in the intensity of the violet color is used to measure the concentration of the drugs. All measurements are made at λ= 520 nm on methanolic solutions of the reagent and drugs. Beer's law is obeyed in the ranges of 5-30 µg/ml (for aceclofenac, diclofenac sodium and thiaprofenic acid), 2-15 µg/ml (for tenoxicam, furosemide and lansoprazole) and 2-12 µg/ml (for benoxinate hydrochloride and ritodrine). The validity of the method was tested by carrying out standard addition procedure analyzing the studied drugs in pure form as well as in their pharmaceutical preparations without interference from common additives. Results of the proposed methods are in good agreement with those of the official or reported methods.

2019 ◽  
Vol 7 (2) ◽  
pp. 52-60 ◽  
Author(s):  
Mykola Blazheyevskiy ◽  
Valeriy Moroz

A new the oxidative derivatization method by means of peroxoacid for the indirect spectrophotometric determination of Periciazine is presented. A potassium hydrogenperoxymonosulfateas a derivatizing agent for Periciazine, yielding the absorbative Periciazine sulfoxide at λmaх=362 nm is proposed. This reaction product was successfully employed for spectrophotometric determination of the Periciazine. The UV spectrophotometric determination of the Periciazine as its sulfoxide proved to be the more simple and selective method. Limit of quantification (LOQ=10S) is 2.8 µg·mL-1. The common excipients employed do not interfere in the determination of phenothiazine drug. Results of analysis of the drug dosage forms by the proposed method are in good agreement with those of the official method. RSD=1.76 % (δ <RSD).


2019 ◽  
Vol 48 (1) ◽  
pp. 29-43
Author(s):  
Paulo Roberto Barrros Gomes ◽  
Victor Elias Mouchrek Filho ◽  
Rayone Wesly Santos de Oliveira ◽  
Adriana Pereira Everton ◽  
Jonas Batista Reis ◽  
...  

Este trabalho descreveu e comparou quatro estudos entre si que utilizaram métodos automáticos em fluxo com detecção espectrofotométrica e a reação de oxidação do diclofenaco para determinar diclofenaco em formulações farmacêuticas e fluidos corporais. Para isso, utilizamos os seguintes artigos: Versatility of a multicommuted flow system in the spectrometric determination of three analytes, Sequential injection spectrophotometric method for the assay of anti-inflammatory diclofenac sodium in pharmaceutical preparations, Screening of conditions controlling spectrophotometric sequential injection analysis e Sequential injection spectrophotometric determination of diclofenac in urine and pharmaceutical formulations e detalhamos as metodologias empregadas, os resultados, conclusões obtidas e comparamos entre eles os limites de detecção, desvio padrão relativo e a frequência analítica. Os resultados mostraram diferenças significativas entre métodos empregados e a utilização do Sistema automático do tipo Análise por Injeção Sequencial, apesar deste possuir menor frequência analítica.


1989 ◽  
Vol 72 (6) ◽  
pp. 885-889 ◽  
Author(s):  
Abdel-Maboud I Mohamed

Abstract A new spectrophotometric method for the determination of some unsubstituted benzene sulfonamides is presented. The method is based on the interaction of these derivatives with 7,7,8,8-tetracyanoquinodimethane at pH 9.0-9.5 to produce intense blue products. The quantitation of the products was carried out at 578 nm. Beer’s law was obeyed over a wide range of concentrations for all sulfonamide compounds studied. Optimum analytical conditions were determined, and the color produced was stable for at least 90 min at 25 °C. Analytical data for determination of sulfonamide compounds in pure form are presented together with application of the proposed method for analysis of some commercially available pharmaceutical preparations. The results are in good agreement with those obtained by official procedures.


2007 ◽  
Vol 90 (2) ◽  
pp. 391-404 ◽  
Author(s):  
Fadia H Metwally ◽  
Yasser S El-Saharty ◽  
Mohamed Refaat ◽  
Sonia Z El-Khateeb

Abstract New selective, precise, and accurate methods are described for the determination of a ternary mixture containing drotaverine hydrochloride (I), caffeine (II), and paracetamol (III). The first method uses the first (D1) and third (D3) derivative spectrophotometry at 331 and 315 nm for the determination of (I) and (III), respectively, without interference from (II). The second method depends on the simultaneous use of the first derivative of the ratio spectra (DD1) with measurement at 312.4 nm for determination of (I) using the spectrum of 40 μg/mL (III) as a divisor or measurement at 286.4 and 304 nm after using the spectrum of 4 μg/mL (I) as a divisor for the determination of (II) and (III), respectively. In the third method, the predictive abilities of the classical least-squares, principal component regression, and partial least-squares were examined for the simultaneous determination of the ternary mixture. The last method depends on thin-layer chromatography-densitometry after separation of the mixture on silica gel plates using ethyl acetatechloroformmethanol (16 + 3 + 1, v/v/v) as the mobile phase. The spots were scanned at 281, 272, and 248 nm for the determination of (I), (II), and (III), respectively. Regression analysis showed good correlation in the selected ranges with excellent percentage recoveries. The chemical variables affecting the analytical performance of the methodology were studied and optimized. The methods showed no significant interferences from excipients. Intraday and interday assay precision and accuracy values were within regulatory limits. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of their pharmaceutical preparations. The validity of the proposed methods was further assessed by applying a standard addition technique. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.


2007 ◽  
Vol 4 (2) ◽  
pp. 173-179 ◽  
Author(s):  
K. Basavaiah ◽  
U. R. Anil Kumar

A simple spectrophotometric method is proposed for the determination of zidovudine(ZDV) in bulk drug and in pharmaceutical preparations. The method is based on the oxidation of ZDV by a known excess of oxidant N-bromosuccinimide (NBS), in buffer medium of pH 1.5, followed by the estimation of unreacted amount of oxidant with metol and sulphanilic acid. The reacted oxidant corresponds to the amount ZDV. The purple-red reaction product absorbs maximally at 530 nm and Beer’s law is obeyed over a range 5 to 75 μg mL-1. The apparent molar absorptivity is calculated to be 5.1×103L mol-1cm-1, and the corresponding Sandell sensitivity value is 0.052 μg cm-2. The limit of detection and quantification are found to be 0.90 and 2.72, respectively. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The method was successfully applied to the assay of ZDV in tablet/capsule preparations and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common tablet/capsule excipients. The accuracy of the method was further ascertained by performing recovery studies via standard-addition method.


1997 ◽  
Vol 30 (15) ◽  
pp. 2743-2753 ◽  
Author(s):  
M. S. Rizk ◽  
Y M Issa ◽  
A F Shoukry ◽  
E M Atia

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