FULL PAPER * E-mail: ubioteck@gmail.com Received April 25, 2010; revised December 28, 2010; accepted January 5, 2011. 1216 © 2011 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Chin. J. Chem. 2011, 29, 1216—1220 Validated Method for the Simultaneous Determination of Lisinopril, Pravastatin, Atorvastatin and Rosuvastatin in API, Formulations and Human Serum by RP-HPLC Najma, Sultana a Arayne, M. Saeed a Safila, Naveed* ,b a United Biotechnologies, Karachi-75290, Pakistan b Faculty of Pharmacy, Hamdard University, Karachi-74600, Pakistan Lisinopril is found to be useful in hypertension and statins as cholesterol lowering drug. Present work was de- signed for the simultaneous determination of lisinopril in presence of pravastatin, atorvastatin, and rosuvastatin us- ing RP-HPLC method. A Purospher star C18 (5 μm, 25×0.46 cm) column was used with mobile phase consisting of acetonitrile∶water (60∶40 V/V, pH 3.0) with flow rate of 1.0 mL•min －1 and the quantitative evaluation was performed at 225 nm. The retention time of lisinopril was 2.0 min and for pravastatin, rosuvastatin and atorvastatin was found to be 3.1, 4.5 and 8.3 min respectively. Suitability of this method for the quantitative determination of the drugs was proved by validation in accordance with the requirements laid down by International Conference on Harmonization (ICH) guidelines. Application of the suggested procedures were successfully applied to the determi- nation of these compounds in active pharmaceutical ingredient and in pharmaceutical preparations, with high per- centage of recovery, good accuracy and precision. Keywords Lisinopril, statins, method validation, HPLC determination Introduction Lisinopril (Figure 1), a synthetic peptide derivative, an oral long-acting, potent angiotensin converting en- zyme (ACE) inhibitor, blocks the angiotensin convert- ing enzyme that cleaves angiotensin I to form the potent vasoconstrictor, angiotensin II, as a result, the blood vessels enlarge or dilate and the blood pressure is re- duced. It is indicated for the treatment of hypertension and congestive heart failure. 1 Figure 1 Structure of Lisinopril. HMG-CoA (3-hydroxy-3-methylglutaryl-CoA) reductase inhibitors, called statins (Figure 2) was a breakthrough in the prevention of hypercholesterolemia and related diseases. 2-4 Cholesterol plays an important role in the everyday functioning of the body. Unfortu- nately, it can also have a negative effect, contributing to the development of atherosclerosis. These plaques can block the arteries, cutting off blood flow, or rupturing and causing a clot that increases blockage. The results Figure 2 Structure of three kinds of statins.