scholarly journals Development and validation of a simple spectrophotometric method for the determination of methyldopa in both bulk and marketed dosage formulations

2014 ◽  
Vol 50 (3) ◽  
pp. 573-582 ◽  
Author(s):  
Paulo Roberto da Silva Ribeiro ◽  
Reginária Morais Duarte

A simple, precise, sensitive, rapid, specific and economical spectrophotometric method was developed to determine methyldopa (MTD) content in bulk and pharmaceutical dosage formulations. The proposed method was based on the formation of a colored product from the nitrosation reaction of MTD with sodium nitrite in an acid medium. The resultant nitroso derivative species reacts further with sodium hydroxide and is converted it into a more stable compound. This yellow nitrosation product exhibited an absorption maximum at 430 nm. Beer's Law was obeyed in a concentration range of 6.37 to 82.81 μg mL-1 MTD with an excellent coefficient of determination (R2 = 0.9998). No interference was observed from common excipients in formulations. The results showed the method to be simple, accurate and readily applied for the determination of MTD in pure form and in pharmaceutical preparations. The analytical results obtained for these products using the proposed method are in agreement with those of the Brazilian Pharmacopoeia procedure at a 95% confidence level.

2018 ◽  
Vol 35 (3) ◽  
pp. 45
Author(s):  
C. Bala Sekaran ◽  
A. Prameela Rani

A simple, sensitive and reproducible spectrophotometric method was developed for the determination of sitagliptin phosphate in bulk and in pharmaceutical formulations. The proposed method is based on condensation of the primary amino group of sitagliptin phosphate with acetyl acetone and formaldehyde producing a yellow colored product, which is measured spectrophotometrically at 430nm. The color was stable for about 1 hour. Beer’s law is obeyed over a concentration range of 5-25 μg/ml. The apparent molar absorptivity and Sandell sensitivity values are 1.067 x 104 Lmol-1cm-1 and 0.0471 μgcm-2 respectively. All the variables were studied to optimize the reaction conditions. No interference was observed in the presence of common pharmaceutical excipients. The validity of the method was tested by analyzing sitagliptin phosphate in its pharmaceutical preparations. Good recoveries were obtained. The developed method was successfully employed for the determination of sitagliptin phosphate in various pharmaceutical preparations.


Author(s):  
Ayya Rajendra Prasad ◽  
Jayanthi Vijaya Ratna

 Objective: The objective of this study was developed and validated a novel, specific, precise, and simple ultraviolet (UV)-spectrophotometric method for the estimation of norfloxacin present in taste masked drug-resin complex.Methods: UV-spectrophotometric determination was performed with ELICO SL 1500 UV-visible spectrophotometer using 0.1 N HCl as a medium. The spectrum of the standard solution was run from 200 to 400 nm range for the determination of absorption maximum (λ max). λ max of norfloxacin was found at 278 nm. The absorbance of standard solutions of 1, 2, 3, 4, and 5 μg/ml of drug solution was measured at an absorption maximum at 278 nm against the blank. Then, a graph was plotted by taking concentration on X-axis and absorbance on Y-axis which gave a straight line. Validation parameters such as linearity and range, selectivity and specificity, limit of detection (LOD) and limit of quantification (LOQ), accuracy, precision, and robustness were evaluated as per the International Conference on Harmonization (ICH) guidelines.Results: Linearity for the UV-spectrophotometric method was noted over a concentration range of 1–5 μg/ml with a correlation coefficient of 0.9995. The LOD and LOQ for norfloxacin were found at 0.39 μg/ml and 1.19 μg/ml, respectively. Accuracy was in between 99.00% and 99.17%. % relative standard deviation for repeatability, intraday precision, and interday precision was found to be 0.600, in between 0.291 and 0.410, and in between 0.682 and 1.439, respectively. The proposed UV spectrophotometric method is found to be robust.Conclusion: The proposed UV-spectrophotometric method was validated according to the ICH guidelines, and results and statistical parameters demonstrated that the developed method is sensitive, precise, reliable, and simple for the estimation of norfloxacin present in taste masked drug-resin complex.


2018 ◽  
Vol 10 (1) ◽  
pp. 74 ◽  
Author(s):  
Ayya Rajendra Prasad ◽  
Bannaravuri Thireesha

Objective: To develop and validate a novel, specific, precise and simple UV-spectrophotometric method for the estimation of lornoxicam present in microsponges.Methods: UV-spectrophotometric determination was performed with Thermo Scientific Evolution 201 UV-Vis spectrophotometer using methanol as a medium. The spectrum of the standard solution was run from 200-400 nm range for the determination of absorption maximum (λ max). λ max of lornoxicam was found at 353 nm. The absorbance of standard solutions of 3, 6, 9, 12 and 15, µg/ml of drug solution was measured at an absorption maximum at 353 nm against the blank. Then a graph was plotted by taking concentration on X-axis and absorbance on Y-axis which gave a straight line. Validation parameters such as linearity and range, selectivity and specificity, LOD and LOQ, accuracy, precision and robustness were evaluated as per ICH guidelines.Results: Linearity for the UV-spectrophotometric method was noted over a concentration range of 3.0-15.0 µg/ml with a correlation coefficient of 0.9995. The limit of detection (LOD) and limit of quantification (LOQ) for lornoxicam was found at 1.26 μg/ml and 3.82 μg/ml respectively. Accuracy was in between 99.21 and 99.60%. % RSD for repeatability, intraday precision and interday precision were found to be 0.473, in between 0.478 and 0.619 and in between 0.855 and 1.818 respectively. The proposed UV method is found to be robust.Conclusion: The proposed UV-Visible spectrophotometric method was validated according to the ICH guidelines and results and statistical parameters demonstrated that the developed method is sensitive, precise, reliable and simple for the estimation of lornoxicam present in microsponges.


Author(s):  
WASAN A AL-UZRI

Objective: A simple and sensitive spectrophotometric method has been presented for the determination of phenylephrine hydrochloride by coupling reaction with diazotized sulfacetamide sodium. Methods: The method is based on the diazotization reaction of sulfacetamide sodium with sodium nitrite in the presence of hydrochloric acid to form diazonium salt, which is coupled with the drug in alkaline medium to form azo dye, showing absorption maxima at 425 nm. Results: Calibration plot was linear over the concentration range of 2–24 μg/mL and detection limit of 0.278 μg/mL with a correlation coefficient of 0.9929. All different chemical and physical experimental parameters affecting on the development and stability of the colored product were carefully studied. Conclusions: The proposed method was successfully applied to the determination of phenylephrine in nasal drops with good precision and sensitivity.


2005 ◽  
Vol 30 (3) ◽  
pp. 23-28 ◽  
Author(s):  
P. R. S. Ribeiro ◽  
L. Pezza ◽  
H. R. Pezza

A new, simple, precise, rapid and low-cost spectrophotometric method for methyldopa determination in pharmaceutical preparations is described. This method is based on the complexation reaction of methyldopa with molybdate. Absorbance of the resulting yellow coloured product is measured at 410 nm. Beer's Law is obeyed in a concentration range of 50 - 200 µg ml-1 methyldopa with an excellent correlation coefficient (r = 0.9999). No interference was observed from common excipients in formulations. The results show a simple, accurate, fast and readily applied method to the determination of methyldopa in pharmaceutical products. The analytical results obtained for these products by the proposed method are in agreement with those of the Brazilian Pharmacopoeia procedure at 95% confidence level.


Author(s):  
Ware Agasti L. ◽  
Pekamwar S. S.

The accurate, precise, sensitive and economical spectrophotometric bioanalytical method was developed and validated for estimation of candesartan in plasma. The UV method was also employed for estimation of candesartan in bulk drug and in dosage form. The absorption maximum found for candesartan was 245nm. The correlation coefficient was found to be 0.999. The mean recovery for candesartan was found to be 99.92%. The developed method was validated according to ICH guidelines and values of accuracy, precision and other statistical analysis were found to be in good accordance with the prescribed values. Thus the proposed method was successfully applied for estimation of candesartan in plasma and for routine industrial work.


Author(s):  
Hind Hadi ◽  
Gufran Salim

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.


Author(s):  
RUAA MUAYAD MAHMOOD ◽  
HAMSA MUNAM YASSEN ◽  
SAMAR , NAJWA ISSAC ABDULLA AHMED DARWEESH ◽  
NAJWA ISSAC ABDULLA

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.


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