Novel microwell-based spectrophotometric assay for determination of atorvastatin calcium in its pharmaceutical formulations

Abstract

The formation of a colored charge-transfer (CT) complex between atorvastatin calcium (ATR-Ca) as a n-electron donor and 2, 3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as a π-electron acceptor was investigated, for the first time. The spectral characteristics of the CT complex have been described, and the reaction mechanism has been proved by computational molecular modeling. The reaction was employed in the development of a novel microwell-based spectrophotometric assay for determination of ATR-Ca in its pharmaceutical formulations. The proposed assay was carried out in 96-microwell plates. The absorbance of the colored-CT complex was measured at 460 nm by microwell-plate absorbance reader. The optimum conditions of the reaction and the analytical procedures of the assay were established. Under the optimum conditions, linear relationship with good correlation coefficient (0.9995) was found between the absorbance and the concentration of ATR-Ca in the range of 10-150 μg/well. The limits of detection and quantitation were 5.3 and 15.8 μg/well, respectively. No interference was observed from the additives that are present in the pharmaceutical formulation or from the drugs that are co-formulated with ATR-Ca in its combined formulations. The assay was successfully applied to the analysis of ATR-Ca in its pharmaceutical dosage forms with good accuracy and precision. The assay described herein has great practical value in the routine analysis of ATR-Ca in quality control laboratories, as it has high throughput property, consumes minimum volume of organic solvent thus it offers the reduction in the exposures of the analysts to the toxic effects of organic solvents, and reduction in the analysis cost by 50-fold. Although the proposed assay was validated for ATR-Ca, however, the same methodology could be used for any electron-donating analyte for which a CT reaction can be performed.

Analytical Methods for the Determination of Rosuvastatin in Pharmaceutical Formulations and Biological Fluids: A Critical Review

“…[54,[130][131][132][133][134][135][136][137][138] A microwell-based automated spectrophotometric method for determination of drugs using a colored charge-transfer (CT) complex has been developed as an alternative for the conventional spectrophotometric technique. [137][138][139][140] This non-conventional spectrophotometric assay demonstrated advantages, such as automation, lower consumption of organic solvents, and relative sensitivity with the limit of quantification of 7.85 mg/well for the quantification of ROS. [138] Immunoassays have been widely used in pharmaceutical and clinical analysis of drugs.…”

Comparative assessment of different marketed brands of atorvastatin tablets in Asir region, Saudi Arabia

“…The samples were analyzed spectrophotometrically at 246nm. [15][16] The release kinetics was fitted into various models using PCP dissolution v 2.08 software.…”

Spectrophotometric Determination of Atorvastatin Calcium and Rosuvastatin Calcium in Bulk and Dosage Form Using P-Dimethylaminobenzaldehyde

“…The proposed methods were applied to the analysis of the drug in dosage forms and the results were statistically compared with reference methods [39,40] by calculating Student's t-and F-values. The evaluated t-and F-values were less than the tabulated values at the 95% confidence level and the results are listed in Table 6 showing that there is no statistical significance difference between the proposed and reference methods.…”