scholarly journals Spot-test identification and rapid quantitative sequential analysis of dipyrone

2010 ◽  
Vol 35 (1) ◽  
pp. 41-46 ◽  
Author(s):  
M. Tubino ◽  
A. C. Biondo ◽  
M. M. D. C. Vila ◽  
L. Pezza ◽  
H. R. Pezza

A qualitative spot-test and tandem quantitative analysis of dipyrone in the bulk drug and in pharmaceutical preparations is proposed. The formation of a reddish-violet color indicates a positive result. In sequence a quantitative procedure can be performed in the same flask. The quantitative results obtained were statistically compared with those obtained with the method indicated by the Brazilian Pharmacopoeia, using the Student's t and the F tests. Considering the concentration in a 100 µL aliquot, the qualitative visual limit of detection is about 5×10-6 g; instrumental LOD ≅ 1.4×10-4 mol L-1 ; LOQ ≅ 4.5×10-4 mol L-1.

2018 ◽  
Vol 35 (1) ◽  
pp. 41
Author(s):  
Matthieu Tubino ◽  
A. C. Biondo ◽  
Marta Maria Duarte Carvalho Vila ◽  
Leonardo Pezza ◽  
Helena Redigolo Pezza

A qualitative spot-test and tandem quantitative analysis of dipyrone in the bulk drugand in pharmaceutical preparations is proposed. The formation of a reddish-violet  color indicates a positive result. In sequence a quantitative procedure can be performed in the same flask. The quantitative results obtained were statistically compared with those obtained with the method indicated by the Brazilian  Pharmacopoeia, using the Student’s t and the F tests. Considering the concentration in a 100 μL aliquot, the qualitative visual limit of detection is about 5×10-6 g; instrumental LOD ≅ 1.4×10-4 mol L-1 ; LOQ ≅ 4.5×10-4 mol L-1.


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.


2018 ◽  
Vol 33 (2) ◽  
pp. 21
Author(s):  
Kanakapura Basavaiah ◽  
Okram Zenita Devi

Two sensitive spectrophotometric methods are described for the determination of simvastatin (SMT) in bulk drug and in tablets. The methods are based on the oxidation of SMT by a measured excess of cerium (IV) in acid medium followed by determination of unreacted oxidant by two different reaction schemes. In one procedure (method A), the residual cerium (IV) is reacted with a fixed concentration of ferroin and the increase in absorbance is measured at 510 nm. The second approach (method B) involves thereduction of the unreacted cerium (IV) with a fixed quantity of iron (II), and the resulting iron (III) is complexed with thiocyanate and the absorbance measured at 470 nm. In both methods, the amount of cerium (IV) reacted corresponds to SMT concentration. The experimental conditions for both methods were optimized. In method A, the absorbance is found to increase linearly with SMT concentration (r = 0.9995) whereas in method B, the same decreased (r = -0.9943). The systems obey Beer’s law for 0.6-7.5 and 0.5-5.0 μg mL-1 for method A and method B, respectively. The calculated molar absorptivity values are 2.7 X 104 and 1.06 X 105 Lmol-1 cm-1, respectively; and the corresponding sandel sensitivity values are 0.0153 and 0.0039μg cm-2, respectively. The limit of detection (LOD) and quantification (LOQ) are reported for both methods. Intra-day and inter-day precision, and accuracy of the methods were established as per the current ICH guidelines. The methods were successfully applied to the determination of SMT in tablets 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 excipients added to tablets. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard addition procedure.


2011 ◽  
Vol 17 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Zenita Devi ◽  
K. Basavaiah ◽  
K.B. Vinay

Three simple and sensitive spectrophotometric methods are described for the determination of domperidone (DOM) in bulk drug and in dosage forms using bromate-bromide mixture as brominating agent in acid medium and three dyes, meta-cresol purple (MCP), amaranth (AMR) and erioglaucine (EGC). The methods involve the addition of a known excess of bromate-bromide mixture to an acidified solution of DOM followed by the determination of the residual bromine by reacting with a fixed amount of either MCP dye and measuring the absorbance at 530 nm (method A) or AMR dye and measuring the absorbance at 520 nm (method B) or EGC dye and measuring the absorbance at 630 nm (method C). Beer?s law is obeyed over the concentration ranges, 0.63 - 10.0, 0.25-4.0 and 0.13-2.0 ?g mL-1 for method A, method B and method C, respectively. The apparent molar absorptivities are calculated to be 3.751 ? 104, 6.604 ? 104 and 1.987 ? 105 L mol-1cm-1 for method A, method B and method C, respectively and the corresponding sandell sensitivity values are 0.011, 0.006 and 0.002 ?g cm-2. The limit of detection and the limit of quantification are also reported for all the three methods. No interference was observed from common additives found in pharmaceutical preparations. Statistical comparisons of the results with those of the reference method showed an excellent agreement, and indicated no significant difference in accuracy and precision. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard-addition technique.


Author(s):  
Tripti Sharma ◽  
Sudan Chandra Si.

<p><strong>Objective: </strong>The objective of this research work was to develop a sensitive, precise, specific, linear and stability-indicating gradient HPLC method for the estimation of valsartan in bulk drug and in pharmaceutical preparations.</p><p><strong>Methods: </strong>Chromatographic separation was achieved on C-18 stationary phase with a gradient mobile phase consisting of orthophosphoric acid buffer (the pH of the solution was adjusted to 4.2±0.05 with triethylamine) and methanol. The eluent was monitored with PDA detector at 225 nm with a flow rate of 1.0 ml/min, run time of 65 min.</p><p><strong>Results: </strong>The method was linear over the range of 20-120μg/ml. The correlation coefficient was found to be 0.9994±0.02. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. Valsartan was found to be stable at light and oxidation experiments. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision and robustness. .The LOQ was found to be 0.26µg/ml and the LOD was found to be 0.79µg/ml.<strong> </strong>Valsartan showed good correlation coefficient in the concentration range of 20-120μg/ml. The developed method was compared statistically by applying two-way anova and student's t-test to correlate with an isocratic method and was applied to bulk drug and tablet dosage form. There was no significant difference between the two methods.<strong></strong></p><p><strong>Conclusion: </strong>The proposed method was found to be accurate, precise, sensitive and robust. Hence, it can be used successfully for the routine analysis of valsartan in pharmaceutical formulation and for analysis of stability samples obtained during accelerated stability study.</p>


2020 ◽  
Vol 8 (2) ◽  
pp. 8-14
Author(s):  
Dashne M. Kokhasmail ◽  
Tara F. Tahir ◽  
Kurdistan F. Azeez

A simple, accurate, and sensitive method for the spectrophotometric determination of captopril in bulk and dosage forms is reported. The method is based on the bromination of captopril with excess solution of n-bromosuccinimide (NBS) in HCl acid medium. The excess NBS is pursued by the assessment of the residual NBS based on its ability to bleach the rhodamine B dye and measuring the absorbance at 555 nm. The amount of NBS reacted coincides to the drug content. The different experimental parameters influencing the development and stability of the color are precisely studied and optimized. Beer’s law is valid within a concentration range of 0.3–1.0 μg/mL with a correlation coefficient R2 = 0.991. The limit of detection 0.169 μg/mL is attained and relative standard deviation values for five replicated measurements of 0.3, 0.7, and 1.0 μg/mL captopril were between 0.53% and 2.03%. No interference is detected from prevalent additives found in pharmaceutical preparations. The proposed method is profitably put on to the determination of captopril in the tablet formulations with mean recoveries 98.91–101.27% and the results were statistically confronted with those of a reference method by applying Student’s t-and F-test.


2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.


Author(s):  
MADHURIMA BASAK ◽  
Santhosh Reddy Gouru ◽  
Animesh Bera ◽  
Krishna veni Nagappan

Objective: The present study aims at developing an accurate precise, rapid and sensitive Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) method for assessing Empagliflozin in bulk drug and in the pharmaceutical dosage form. Methods: The proposed method employs a Reverse Phase Shim Pack C18 column (250 mm × 4.6 mm id; 5 µm) using a mobile phase comprising of acetonitrile and water in the ratio of 60:40 v/v flushed at a flow rate of 1 ml/min. The eluents were monitored at 223 nm. Results: Empagliflozin was eluted at a retention time of 5.417 min and established a co-relation co-efficient (R2>0.999) over a concentration ranging from 0.0495-100µg/ml. Percentage recovery was obtained between 98-102% which indicated that the method is accurate. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) were found at 0.0125µg/ml and 0.0495µg/ml, respectively. Conclusion: An RP-HPLC method which was relatively simple, accurate, rapid and precise was developed and its validation was performed for the quantitative analysis of empagliflozin in bulk and tablet dosage form (10 and 25 mg) in accordance to International Conference of Harmonization (ICH) Q2 (R1) guidelines. The proposed method may aid in routinely analyzing empagliflozin in pharmaceuticals.


Author(s):  
Anas Rasheed ◽  
Osman Ahmed

A specific, precise, accurate ultra pressure liquid chromatography (UPLC) method is developed for estimation of chlophedianol hydrochloride in bulk drug and syrup dosage form. The method employed with Hypersil BDS C18 (100 mm x 2.1 mm, 1.7 μm) in a gradient mode, with mobile phase of methanol and acetonitrile in the ratio of 65:35 %v/v. The flow rate was 0.1 ml/min and effluent was monitored at 254 nm. Retention time was found to be 1.130±0.005 min. The method was validated in terms of linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ)in accordance with ICH guidelines. Linear regression analysis data for the calibration plot showed that there was good linear relationship between response and concentration in the range of 20-100 μg/ml respectively. The LOD and LOQ values were found to be 2.094(μg/ml)and 6.3466(μg/ml)respectively. No chromatographic interference from syrup excipients and degradants were found. The proposed method was successfully used for estimation of chlophedianol hydrochloride in syrup dosage form.


2015 ◽  
Vol 12 (1) ◽  
pp. 167-177 ◽  
Author(s):  
Baghdad Science Journal

A spectrophotometric method has been proposed for the determination of two drugs containing phenol group [phenylephrine hydrochloride (PHP) and salbutamol sulphate (SLB)] in pharmaceutical dosage forms. The method is based on the diazotization reaction of metoclopramide hydrochloride (MCP) and coupling of the diazotized reagent with drugs in alkaline medium to give intense orange colored product (?max at 470 nm for each of PHP and SLB). Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. Under the proposed optimum condition, Beer’s law was obeyed in the concentration range of 1-32 and 1-14 ?g mL-1 for PHP and SLB, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for each of PHP and SLB were 0.60, 0.52 ?g mL-1 and 2.02, 1.72 ?g mL-1, respectively. No interference was observed from common excipients present in pharmaceutical preparations. The good correlation coefficients and low relative standard deviation assert the applicability of this method. The suggested method was further applied for the determinations of drugs in commercial pharmaceutical preparations, which was compared statistically with reference methods by means of t- test and F- test and were found not to differ significantly at 95% confidence level. The procedure was characterized by its simplicity with accuracy and precision.


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