Simultaneous Spectrophotometric Determination of Lamivudine and Stavudine using π-Acceptors as Analytical Reagents

2020 ◽  
Vol 5 (3) ◽  
pp. 234-241
Author(s):  
Sayanna ◽  
T. Veeraiah ◽  
Ch. Venkata Ramana Reddy

Two new sensitive and precise spectrophotometric methods have been proposed and developed for the simultaneous estimation of lamivudine and stavudine in pure mixture and in pharmaceutical binary dosage forms. A new concept of area under curve (AUC) is proposed for simultaneous estimation of two drugs by these methods. Method A involves the use of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as analytical reagent and the AUC between 390 nm and 690 nm for DDQ was used for determination. Method B involves the use of p-chloranilic acid: 2,5-dichloro-3,6-dihydroxy-1,4- benzoquinone (p-CA) as an analytical reagent and the AUC between 400 and 700 nm for p-chloranilic acid was used for deter-mination. The methods developed and construction of calibration curves using two analytical reagents viz., DDQ and p-chloranilic acid are described. Optical and analytical parameters for the individual and simultaneous determination of lamivudine and stavudine using AUC are tabulated. The methods have been validated and compared with HPLC methods in terms of standard deviation, t-test and F-test.

Author(s):  
Veeraiah T ◽  
Ravi M ◽  
Ch Venkata Ramana Reddy

In this study, two sensitive and precise spectrophotometric methods have been developed for the simultaneous determination of azithromycin and ofloxacin in pure mixture and in pharmaceutical binary dosage forms. A new concept of area under curve (AUC) is proposed for simultaneous estimation of two drugs by these methods. Method A involves the use of DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) as analytical reagent and the AUC between 390nm and 690nm for DDQ was used for determination. Method B involves the use of p-CA (p-chloranilic acid: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone) as an analytical reagent and the AUC between 400nm and 700nm for p-CA was used for determination. The methods developed and construction of calibration curves using two analytical reagents viz., DDQ and p-CA are described. Optical and analytical parameters for the individual and simultaneous determination of azithromycin and ofloxacin using AUC are tabulated. These methods have been validated and compared with HPLC methods in terms of standard deviation, t-test and F-test.


2008 ◽  
Vol 3 ◽  
pp. ACI.S643 ◽  
Author(s):  
Nafisur Rahman ◽  
Sk Manirul Haque

Four simple, rapid and sensitive spectrophotometric methods have been proposed for the determination of enalapril maleate in pharmaceutical formulations. The first method is based on the reaction of carboxylic acid group of enalapril maleate with a mixture of potassium iodate (KIO3) and iodide (KI) to form yellow colored product in aqueous medium at 25 ± 1°C. The reaction is followed spectrophotometrically by measuring the absorbance at 352 nm. The second, third and fourth methods are based on the charge transfer complexation reaction of the drug with p-chloranilic acid (pCA) in 1, 4-dioxan-methanol medium, 2, 3-dichloro 5, 6-dicyano 1, 4-benzoquinone (DDQ) in acetonitrile-1,4 dioxane medium and iodine in acetonitrile-dichloromethane medium. Under optimized experimental conditions, Beer's law is obeyed in the concentration ranges of 2.5-50, 20-560, 5-75 and 10-200 µg mL-1, respectively. All the methods have been applied to the determination of enalapril maleate in pharmaceutical dosage forms. Results of analysis are validated statistically.


2010 ◽  
Vol 7 (s1) ◽  
pp. S344-S348 ◽  
Author(s):  
R. Rote Ambadas ◽  
P. Pingle Sunita

Two simple, economic and accurate UV spectrophotometric methods have been developed for determination of gemifloxacin mesylate in pharmaceutical tablet formulation. The first UV-spectrophotometric method depends upon the measurement of absorption at the wavelength 263.8 nm. In second area under curve method the wavelength range for detection was selected from 268.5-258.5 nm. Beer’s law was obeyed in the range of 2 to 12 μgmL-1for both the methods. The proposed methods was validated statistically and applied successfully to determination of gemifloxacin mesylate in pharmaceutical formulation.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Serife Evrim Kepekci Tekkeli ◽  
Armağan Önal ◽  
Fatemeh Bahadori

This study presents three simple, rapid, and accurate spectrophotometric methods for the determination of Rasagiline (RSG) in pharmaceutical preparations. The determination procedures depend on the reaction of RSG with chloranilic acid for method A, tetrachloro-1,4-benzoquinone for method B, and 7,7,8,8-tetracyanoquinodimethane for method C. The colored products were quantitated spectrophotometrically at 524, 535, and 843 nm for methods A, B, and C, respectively. Different variables affecting the reaction were optimized. Linearity ranges of the methods with good correlation coefficients (0.9988–0.9996) were observed as 25–300 µg mL−1, 25–350 µg mL−1, and 50–500 µg mL−1for methods A, B, and C, respectively. The formation of products takes place through different mechanisms. The sites of interaction were confirmed by elemental analysis using IR and1H-NMR spectroscopy. The validation of the methods was carried out in terms of specificity, linearity, accuracy, precision, robustness, limit of detection, and limit of quantitation. No interference was observed from concomitants usually present in dosage forms. The methods were applied successfully to the determination of RSG in pharmaceutical preparations.


2006 ◽  
Vol 3 (3) ◽  
pp. 142-145
Author(s):  
P. Ravi Kumar ◽  
P. Bhanu Prakash ◽  
M. Murali Krishna ◽  
M. Santha Yadav ◽  
C. Asha Deepthi

Domperidone is an antiemetic and pantoprazole is an antiulcer drug. Simple, precise, rapid and selective simultaneous equation and Q- analysis UV spectrophotometric methods have been developed for the simultaneous determination of domperidone and pantoprazole from combined tablet dosage forms. The methods involve solving of simultaneous equations and Q-value analysis based on measurement absorptivity at 216, 287 and 290 nm respectively. Linearity lies between 1-15 mcg/mL for domperidone and 0-50 mcg/mL for pantoprazole.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shilan A. Omer ◽  
Nabil A. Fakhre

In this study, three simple and accurate spectrophotometric methods for simultaneous determination of pyriproxyfen and chlorothalonil residues in cucumbers and cabbages grown in experimental greenhouse were studied. The first method was based on the zero-crossing technique measurement for first and second derivative spectrophotometry. The second method was based on the first derivative of the ratio spectra. However, the third method was based on mean centering of ratio spectra. These procedures lack any previous separation steps. The calibration curves for three spectrophotometric methods are linear in the concentration range of 1–30 μg·mL−1 and 0.5–7 μg·mL−1 for pyriproxyfen and chlorothalonil successively. The recoveries ranged from 82.12–97.40% for pyriproxyfen and 81.51–97.04% for chlorothalonil with relative standard deviations less than 4.95% and 5.45% in all instances for pyriproxyfen and chlorothalonil, respectively. The results obtained from the proposed methods were compared statistically by using one-way ANOVA, and the results revealed there were no significant differences between ratio spectra and mean centering methods with the zero-crossing technique. The proposed methods are successfully applied for the simultaneous estimation of the residue of both pesticides in cucumber and cabbage samples.


Author(s):  
Zeinab Adel Nasr ◽  
Noha S. Said ◽  
Sawsan A. Abdel-Razeq

Aims: Two spectrophotometric methods were developed and validated for the determination of sofosbuvir in presence of its alkaline degradate. Study Design: Ratio difference and ratio derivative methods were assisted for determination of sofosbuvir in presence of its alkaline degradate, laboratory-prepared mixtures and in tablet dosage forms. Place and Duration of Study: Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy (Girls), Al - Azhar University, between December 2019 and January 2020. Methodology: Two analytical methods were achieved and validated for the quantitative determination of Sofosbuvir in presence of its alkaline degradate. The first method was ratio difference (RD) method, where the UV absorption spectra of different concentrations of sofosbuvir were divided by the spectrum of a certain concentration (15 µg mL-1) as a devisor of its alkaline degradate to get the ratio difference spectra. Afterwards, the peak amplitudes difference between 253.7 and 243.5 nm were measured. The second method was the ratio derivative (1DR) method, where the first derivative of the ratio spectra (1DR) was obtained and its amplitude was measured at 247 and 268 nm. Good linearity was obtained over the concentration range of 3-15 µg mL-1 for the proposed methods. The proposed procedures were adopted for the selective determination of intact Sofosbuvir in presence of up to 80% of its degradation product. Sofosbuvir was exposed to different conditions as alkaline, acidic and oxidative degradation. Results: The proposed methods were developed and validated with good linearity range of 3-15 µg mL-1 for both methods, and also with good accuracy and precision. And the obtained results were statistically compared to those obtained by the reported method. Conclusion: Sofosbuvir was successfully determined by the proposed ratio difference and ratio derivative methods in bulk powder, laboratory prepared mixtures and tablet dosage form with good accuracy and precision. The methods were validated according to ICH guidelines. The results obtained were compared with those of the reported method and were found to be in good agreement.


2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Ashraf M. Mahmoud

New rapid, sensitive, and accurate kinetic spectrophotometric methods were developed, for the first time, to determine omeprazole (OMZ) in its dosage forms. The methods were based on the formation of charge-transfer complexes with both iodine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The variables that affected the reactions were carefully studied and optimized. The formed complexes and the site of interaction were examined by UV/VIS, IR, and1H-NMR techniques, and computational molecular modeling. Under optimum conditions, the stoichiometry of the reactions between OMZ and the acceptors was found to be 1 : 1. The order of the reactions and the specific rate constants were determined. The thermodynamics of the complexes were computed and the mechanism of the reactions was postulated. The initial rate and fixed time methods were utilized for the determination of OMZ concentrations. The linear ranges for the proposed methods were 0.10–3.00 and 0.50–25.00   with the lowest LOD of 0.03 and 0.14   for iodine and DDQ, respectively. Analytical performance of the methods was statistically validated; RSD was <1.25% for the precision and <1.95% for the accuracy. The proposed methods were successfully applied to the analysis of OMZ in its dosage forms; the recovery was 98.91–100.32%  0.94–1.84, and was found to be comparable with that of reference method.


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