Cerimetric determination of simvastatin in pharmaceuticals based on redox and complex formation reactions



Document title: Cerimetric determination of simvastatin in pharmaceuticals based on redox and complex formation reactions
Journal: Ecletica quimica
Database: PERIÓDICA
System number: 000366945
ISSN: 0100-4670
Authors: 1
1
Institutions: 1University of Mysore, Department of Chemistry, Manasagangotri, Mysore. India
Year:
Season: Abr-Jun
Volumen: 33
Number: 2
Pages: 21-28
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental
English abstract 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 the reduction 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
Disciplines: Química,
Medicina
Keyword: Química analítica,
Química farmacéutica,
Terapéutica y rehabilitación,
Simvastatina,
Cerimetría,
Espectrofotometría,
Productos farmacéuticos
Keyword: Chemistry,
Medicine,
Analytical chemistry,
Medicinal chemistry,
Therapeutics and rehabilitation,
Simvastatin,
Cerimetry,
Spectrophotometry,
Pharmaceuticals
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