New Validated Fluorescence Quenching Based Procedure for the Determination of Cilostazol and Clopidogrel in Bulk, Tablets and Biological Fluids, With Application of Stern-volmer Equation
F. Ibrahim
Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, 35516, Mansoura, Egypt.
M. Sharaf El-Din
Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, 35516, Mansoura, Egypt.
Heba Abd El-Aziz *
Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, 35516, Mansoura, Egypt.
*Author to whom correspondence should be addressed.
Abstract
Aims: A very Sensitive, simple and selective Spectrofluorimetric method for the determination of Cilostazol or Clopidogrel through their reaction with fluorescein dye is developed. Determination was performed on raw material, tablet dosage form and extended for determination of cilostazol in spiked human plasma.
Study Design: Quenching reaction between fluorescein dye and tertiary amine containing drugs.
Place and Duration of the Study: This experiment was applied on analytical chemistry lab in faculty of pharmacy, analytical chemistry department, during the period (from 5 April to 10 May, 2016).
Methodology: The formed ion-pair complex between the reagent and each drug results in decrease in the fluorescence intensity of the reagent, this decrease (fluorescence quenching ΔF) is directly proportional to concentration of both drugs at the range of (0.001-0.08 μg ml-1) and (0.01-0.50 μg ml-1) for cilostazol (CIL) and Clopidogrel (CLP), respectively. For cilostazol (limit of detection) LOD is (0.0003μg mL-1) and (limit of quantitation) LOQ is (0.0008 μg ml-1). For clopidogrel LOD is (0.0025 μg ml-1) and LOQ is (0.0076 μg ml-1). The affecting factors on fluorescence intensity of the product are carefully investigated and optimized. Using the optimized experimental conditions, the proposed quenching method is validated according to International Conference of Harmonization guidelines. The proposed method is perfectly applied to the analysis of commercial tablets containing each drug separately.
Results: Statistical comparisons of the results with those of the reference methods illustrate good agreement and confirm that there was no significant difference in the accuracy and precision between the proposed and reference one for both drugs, respectively. The proposed method is extended for the in vitro determination of CIL in spiked human plasma as preliminary investigation; the mean recovery (n=5) was 99.80.
Conclusion: Owing to the simplicity, quickness and cheapness of the present study, it can be applied for the routine quality control of the studied drug in its dosage forms.
Keywords: Cilostazol (CIL), Clopidogrel (CLP), fluorescein, spectrofluorimetric, quenching, tablet dosage form