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Conversion investigation for lovastatin and its derivatives by HPLC
Zhibing Huang1, Yang Xu, Yanping Li
1Sino-Germany Joint Research Institute, State Key Laboratory of Food Science, Nanchang University, Nanchang 330047, China.
Journal of Chromatographic Science
|September 8, 2010
Summary
A new HPLC method separates lovastatin (LT) and its derivatives, revealing its conversion into lactone, lovastatin acid (LA), and methyl ester (LM) forms under varying conditions. Methanol in acidic solutions impacts these transformations.
Area of Science:
- Analytical Chemistry
- Pharmaceutical Analysis
Background:
- Lovastatin (LT) is a crucial pharmaceutical compound.
- Understanding its stability and degradation pathways is essential for accurate quantification.
Purpose of the Study:
- To develop a high-performance liquid chromatography (HPLC) method for separating lovastatin and its derivatives.
- To investigate the conversion of lovastatin and its derivatives in alkaline and acidic solutions over time.
Main Methods:
- Development of an HPLC method using a Symmetry C18 column and an acetonitrile-water mobile phase (77:23, v/v) at pH 3.0.
- Analysis of lovastatin (LT) conversion into lovastatin acid (LA) and its methyl ester (LM) under different storage conditions (alkaline, acidic, varying methanol concentrations).
Main Results:
- Successfully separated three forms of lovastatin: lactone (LT), lovastatin acid (LA), and methyl ester (LM) with distinct retention times.
- Observed that LT converts to LA in 0.1 M NaOH.
- Under acidic conditions, LT converts to LA, which then transforms into LT and LM, reaching equilibrium after 60 hours, influenced by methanol concentration.
Conclusions:
- The developed HPLC method effectively separates lovastatin and its key derivatives.
- Methanol concentration and storage time significantly influence the equilibrium between lovastatin forms in acidic solutions.
- Excluding methanol from acidic extraction solutions is recommended for accurate determination and separation of lovastatin acid and lovastatin.
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