A New Simultaneous Determination of Rosuvastatin Calcium and its Lactone Impurity by Reverse Phase HPLC Method

A reliable, sensitive and stability -indicating reverse phase HPLC method was developed for the determination of Rosuvastatin calcium and its lactone impurity in drug substance and pharmaceutical dosage form. Rosuvastatin calcium was fourth highest selling drug in the United States, accounting approximately $5.2 billion in the year of 2013, which is used for the treatment of hypercholesterolemia. The resolution between Rosuvastatin and lactone impurity was good with resolution factors more than 10.0. The chromatographic separation was achieved on a sunfire column C18 (250 x 4.6 mm, 5 μm) with mobile phase containing a gradient mixture of solvent-A (10 mM ammonium acetate) and solvent-B (acetonitrile: methanol (50:50 v/v)). The eluted compounds were monitored at 242 nm and the total run time was 15 minutes. Degradation behavior of the Rosuvastatin calcium was studied under various degradation stress conditions. The Limit of detection and limit of quantitation of lactone impurity was found to be 0.01μg/mL and 0.04μg/mL, respectively, for 10μL injection volume. The sample solution and mobile phase were stable for at least 48 hours. The proposed accurate method can be useful for quantification of Rosuvastatin calcium and its lactone impurity in the bulk drug substance and also dosage form.