Original Article RAPID, HIGHLY EFFICIENT AND STABILITY INDICATING RP-UPLC METHOD FOR THE QUANTITATIVE DETERMINATION OF POTENTIAL IMPURITIES OF CARVEDILOL ACTIVE PHARMACEUTICAL INGREDIENT SAJAN P. G. 1, , ROHITH T. 2 , SANTOSH PATIL 3 , MANTELINGU K. 4 , RANGAPPA K. S. 5 , KUMARA M. N. 6* 1,2 Deepta Laboratories, No.77-78/1, Vishweshwaranagar, 2 nd stage, Industrial Suburb, Mysore 570008, 3 Biocon Limited, Plot No. 2,3,4,5 & 6, Bommasandra Jigani Link Road, Bangalore, 4,5 Department of Chemistry, Manasagangothri, University of Mysore, Mysore 570006, 6 Chemistry department, Yuvaraja’s College, University of Mysore, Mysore 570005 Email: sajanpg@gmail.com Received: 29 Jul 2014 Revised and Accepted: 10 Sep 2014 ABSTRACT Objective: The main objective of the proposed study was to develop a sensitive, rapid and stability indicating reverse phase UV-UPLC method for the quantitative determination of potential impurities in carvedilol. Methods: The chromatographic separations were achieved on waters Acquity UPLC BEH C18 column (100 mm length 2.1 mm ID with 1.7 μm particle size, Waters corporation, MA, USA). Mobile phase A consisted, 0.04% trifluroacetic acid in water and mobile phase B consisted as 0.04% trifluroacetic acid in acetonitrile with a gradient programme (Tmin A:B) T090:10, T465:35, T740:60, T1020:80, T10.1 90:10. The column temperature was maintained at 60 ° C and the detection was carried out at 240 nm. The flow rate was set to 0.5 mL/min. Results: Efficient chromatographic separation was achieved on UPLC BEH C18 stationary phase in gradient mode using simple mobile phase. In forced degradation study, major degradation of the drug substance was found to occur under oxidative stress conditions to form carvedilol hydroxylamine. The method was validated according to ICH guidelines with respect to specificity, precision, linearity and accuracy. Regression analysis showed the correlation coefficient value greater than 0.999 for carvedilol and its five impurities. Detection limit of impurities was in the range of 0.002–0.004% indicating the high sensitivity of the newly developed method. Accuracy of the method was established based on the recovery obtained between 96.7% and 108.1% for all impurities. Conclusion: A new, rapid and highly efficient UPLC method was developed, which separates all impurities and degradation products of carvedilol. The method has been validated in order to ascertain the suitability and stability indicating power of the method. Keywords: Carvedilol, Impurities, RP-UPLC, Validation, Forced degradation. INTRODUCTION Carvedilol, (±)-1-(carbazol-4-yloxy)-3-((2-o-methoxyphenoxy) ethyl)amino)-2-propanol (Figure 1), is nonselective β-blocking agent with vasodilatation properties attributed mainly to its blocking activity at α1-receptors. Carvedilol has much greater antioxidant activity than other commonly used blockers. It has been prescribed as an antihypertensive agent, an antiangina agent [1-4], and for treatment of congestive heart failure (CHF) [5]. Carvedilol is both a beta blocker (β1, β2) and an alpha blocker (α1), Norepinephrine stimulates the nerves that control the muscles of the heart by binding to the β1- and β2-adrenergic receptors. Carvedilol blocks the binding to those receptors [6] which both slows the heart rhythm and reduces the force of the heart's pumping. This lowers blood pressure thus reducing the workload of the heart, which is particularly beneficial in heart failure patients. Norepinephrine also binds to the α1-adrenergic receptors on blood vessels, causing them to constrict and raise blood pressure. Carvedilol blocks this binding to the α1-adrenergic receptors too [7], which also lower blood pressure. Carvedilol is a racemic compound and the stereoselectivity of the carvedilol enantiomers was established. The effects of the levorotatory S(-)-enantiomer are vasodilatation and beta blocking. The R(+)-enantiomer is a pure vasodilatation agent. HPLC methods for the determination of carvedilol related impurities were reported in USP, EP and BP [8-9]. Different analytical methods have been reported for the determination of carvedilol, its metabolites and enantiomers including liquid chromatography, liquid chromatography-mass spectrometry-mass spectrometry (HPLC/MS/MS), and electrophoresis [10-15]. Ultra Performance Liquid Chromatography (UPLC) is a relatively new technique giving new possibilities in liquid chromatography, especially concerning the decrease of time and solvent consumption. The separation on UPLC is performed under very high pressures (up to 100MPa is possible in UPLC system), but it has no negative influence on the analytical column or other components of chromatographic system. Molecular weight = 406.49, Molecular formula = C24H26N2O4 Fig. 1: Structure of Carvedilol. Separation efficiency remains maintained or is even improved comparing to the conventional system using 5 μm particle packed analytical columns. As it is very well known from Van Deemter equations, the efficiency of the chromatographic process is proportional to particle size decrease. This model describing band broadening, which explains the relationship between the height equivalent of the theoretical plate (HETP) and linear velocity, one of the terms (path dependent term), is dependent on a diameter of particle packed into the analytical column [16]. Detailed literature study shown that there are no UPLC methods reported for the quantification of carvedilol impurities. In the International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 6, Issue 10, 2014 Innovare Academic Sciences