# Introduction torvastatin figure 1 is an HMG-CoA reductase inhibitors (3-hydroxy,3-methylglutaryl-CoA), called statins. It was a breakthrough for the prevention of hypercholesterolemia and related diseases.1-3 Cholesterol has an important role in the daily functioning of the body. But, it can also have a negative effect to the development of atherosclerosis. These plaques can block the arteries, disturb blood flow, or may rupturing and causing a clot that increases blockage. The results of these blockages are very serious and can cause angina, claudication, stroke and heart attack.4 Hyperlipidemia and hypertension are correlated to each other and have additional effect on CHD coronary heart disease and associated mortality rate, since CV cardiovascular disease is closely related to some factors such as high cholesterol levels, hypertension or diabetes. In literature there are many evidences which suggest additive beneficial effects of statin combined with losartan in the treatment of hypercholesterolemia, hypertensive patients.5 There are several methods reported by HPLC with the statin 6-10 but there is study found that show the comparison of available brands in market.Because the therapy is very expensive an person who has any cardiovascular disorder take medicine life time when he started.Therefor it is important that they use medicine should not be expensive and give hundred % result. Author: Faculty of Pharmacy Jinnah University for Women Karachi. e-mail: safila117@yahoo.com There for in the mind of this I have checked the % assay of different brands available in the market . The aim of this study is to investigate the assay of commercially available six brands of atorvastatin in Karachi, Pakistan. number and were labeled to conatin atorvastatin 10mg per tablet. All the six brands have 5 year shelf life. The serial number as an identification of purchased brands are given in Tabel 1.20 tablets of six different brand of atorvastatin from the marketed sample were weighed and crushed uniformly with the help of a mortar and pestle. By calculating the average weighed sample powder equivalent to 10 mg of atorvastatin was transferred into a volumetric flask containing 10mL methanol solvent MeOH. The solutions were sonicated for about 5 min and than make up volume upto 100 ml with water. # d) Procedure After preparation of standard and tablet solutions, strength of solution 100 ppm in 100 ml absorbance of the sample preparation and standard preparation in 1cm cell at the wavelength of maximum absorbance at about 244 nm, using spectrophotometer, using the blank solution. Calculate the quantity in mg, of atorvastatin per tablet. # III. # Results and Discussions Pharmaceutical assay was carried out by using spectrophotometer on all brands of atorvastatin tablets during the study. Table-1 shows name brand and % assay of different brands. Table-2 ,3 are showing the descriptive within and between groups and shows result are highly significant with p value 0.000. Test of hypothesis i-e ANOVA and multiple comparison of different brands of atorvastatin are given in table 3 shows highly significant difference of all brands with each other. The proposed method for the assay of commercially available atorvastatin tablet formulation is very simple, accurate ,least time consuming and rapid. It can be easily used for routine quality control QC for monitoring the assay in the API, inprocess samples and tablet formulation. ANOVA shows between and within group F value 309348.804 with degree of freedom df value5 and 24 and p value 0.00 which shows significant results. 1![Figure 1 : Structure of Atorvastatin II.](image-2.png "Figure 1 :") 1Brand Name Serial noAverage wt of tablet mgWt for 100 ppmAbsorbance 244 nm% assayProstatinATR-116.4316.430.157104.66StatinATR-216.616.60.13791.33FopsecATR-315.915.90.09966.00WinstorATR-415.615.60.11878.66SurviveATR-518.818.80.05939.33 2Sum of SquaresdfMean SquareFSig.Between Groups13328.35152665.670309348.804.000Within Groups.20724.009Total13328.55729Figure 1 5%Availability ofdifferent brands150100500ATR-ATR-ATR-ATR-ATR-ATR-123456ATR213.30467 *.05871.00013.183513.4258ATR338.56733 *.05871.00038.446238.6885ATR1ATR425.96600 *.05871.00025.844826.0872ATR565.29267 *.05871.00065.171565.4138ATR642.53133 *.05871.00042.410242.6525ATR1-13.30467 *.05871.000-13.4258-13.1835ATR325.26267 *.05871.00025.141525.3838ATR2ATR412.66133 *.05871.00012.540212.7825ATR551.98800 *.05871.00051.866852.1092ATR629.22667 *.05871.00029.105529.3478ATR3 ATR4ATR1 ATR2 ATR4 ATR5 ATR6 ATR1 ATR2 ATR3-38.56733 * -25.26267 * -12.60133 * 26.72533 * 3.96400 * -25.96600 * -12.66133 * 12.60133 *.05871 .05871 .05871 .05871 .05871 .05871 .05871 .05871.000 .000 .000 .000 .000 .000 .000 .000-38.6885 -25.3838 -12.7225 26.6042 3.8428 -26.0872 -12.7825 12.4802-38.4462 -25.1415 -12.4802 26.8465 4.0852 -25.8448 -12.5402 12.7225Global Journal ofATR539.32667 *.05871.00039.205539.4478ATR616.56533 *.05871.00016.444216.6865ATR1-65.29267 *.05871.000-65.4138-65.1715ATR2-51.98800 *.05871.000-52.1092-51.8668ATR5ATR3 ATR4-26.72533 * -39.32667 *.05871 .05871.000 .000-26.8465 -39.4478-26.6042 -39.2055ATR6-22.76133 *.05871.000-22.8825-22.6402 © 2014 Global Journals Inc. (US) * JATobert Nat. Rev. Drug Discov 2 2003 * PHJones MHDavidson EAStein HEBays JMMckenney EMiller Am. J. Cardiol 92 2003 * MJCaslake GStewart SPDay EDaly Atherosclerosis 171 2003 * JMMckenney Am. J. Health-Syst. Pharm 62 2005 * KKKoh MJQuon SHHan J. Am. Heart Assoc 110 2004 * Simultaneous Determination of Captopril and Statins in API, Pharmaceutical Formulations and in Human Serum by RP-HPLC NSultana MSArayne SafilaNaveed J. Chin. Chem. Soc 57 2010 * Simultaneous determination of Prazosin, Atorvastatin, Rosuvastatin and Simvastatin in API, Dosage Formulations and Human serum by RP-HPLC NSultana MSArayne SNShah SafilaNaveed Journal of the Chinese Chemical Society 57 6 2010 * Validated Method for the Simultaneous Determination of Lisinopril, Pravastatin, Atorvastatin and Rosuvastatin in API, Formulations and Human Serum by RP-HPLC Chinese NSultana ArayneMs SafilaNaveed 10.1002/cjoc.201190226 Journal of Chemistry 29 2011 * Determination of Enalapril and Statins In Pharmaceutical Formulations by RP-HPLC NSultana ArayneMs SafilaNaveed Chilean chemical society 56 3 2011 * Simultaneous LC Determination of Rosuvastatin, Lisinopril, Captopril, and Enalapril in API MSArayne NSultana ArmanTabassum 10.1007/s00044-012-9997- Pharmaceutical Dosage Formulations, and Human Serum Medicinal Chemistry Research Saeeda Nadir Ali and Safila Naveed 21 2012