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Published on: February 20, 2020
Smart stability-indicating spectrophotometric methods for determination of binary mixtures without prior separation
Mohammad G El-Bardicy1, Hayam M Lotfy, Mohammad A El-Sayed
1Cairo University, Faculty of Pharmacy, Department of Analytical Chemistry, Kaser E1-Aini St, ET 11562, Cairo, Egypt.
Journal of AOAC International
|May 15, 2008
Summary
Two spectrophotometric methods, ratio subtraction and isosbestic point, accurately determine vincamine, even with degradation products. These validated methods are suitable for stability testing in pharmaceutical formulations.
Area of Science:
- Analytical Chemistry
- Spectrophotometry
Background:
- Vincamine analysis is complicated by its acid degradation product.
- Simultaneous determination of cinnarizine (CN) and nicergoline (NIC) presents analytical challenges.
Purpose of the Study:
- To develop and validate two innovative spectrophotometric methods for determining vincamine.
- To analyze vincamine in the presence of its degradation product.
- To quantify cinnarizine (CN) and nicergoline (NIC) in synthetic mixtures.
Main Methods:
- Ratio subtraction spectrophotometry.
- Isosbestic point spectrophotometry.
- Standard addition technique for validation.
Main Results:
- Linear correlations achieved for vincamine (8-40 µg/mL), CN (6-22 µg/mL), and NIC (6-36 µg/mL).
- High accuracies obtained: vincamine (99.72±0.917%), CN (99.91±0.703%), NIC (99.58±0.847% and 99.83±1.039%).
- Ratio subtraction method effective for up to 80% vincamine degradation product.
Conclusions:
- The proposed spectrophotometric methods are reliable and accurate for analyzing vincamine and related compounds.
- These methods are suitable as stability-indicating assays for pharmaceutical formulations.
- The techniques ensure specificity and are validated for practical application.
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