TABLE 1: SYSTEM SUITABILITY TEST PARAMETERS FOR qUINAPRIL AND HYDROCHLOROTHIAZIDE BY PRPPOSED METHOD

1. Budavari S, editors. The Merck index. 13th ed. Whitehouse Station, NJ: Merck and Co., Inc.; 2001. 2. Freerd AL, Steven B, Stilbering SB, Kolodsick KJ, Rossi DT, Mahjour M, et al. Improving the detection of degradants and impurities in pharmaceutical drug products by applying mass spectral and chromatographic searching. Int J Pharm 2005;304:135-44. 3. Abbara GC, Aymad G, Hinh S, Diquett B. Simultaneous determination of quinapril and its active metabolite quinaprilat in human plasma using high performance liquid chromatography with ultraviolet detection. J Chromatogr Anal Technol Biomed Life Sci 2002;76:199-207. 4. Dinc E, Balenu D. Continuous wavelet transform and chemometric methods for quantitative resolution of a binary mixture of quinapril and hydrochlorothiazide in tablets. J Braz Chem Soc 2007;18:962-8. 5. Kowalczuk D, Hopkala H. Application of derivative spectrophotometry for simultaneous determination of quinapril and hydrochlorothiazide in the combination tablets. J AOAC Int 2004;87:847-51. 6. Freed AL, Kale U, Ando H, Rossi DT, Kingsmill CA. The development and stability assessment of extemporaneous pediatric formulations of accupril. J Pharm Biomed Anal 2004;35:727-38. 7. Takubo T, Okada H, Ishii M, Hara K, Ishii Y. Sensitive and selective liquid chromatography-electro spray ionization tandem mass spectrometry analysis of hydrohlorothiazide in rat plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2004;806:199-203. 8. Ramakrishna NVS, Vishwottam KN, Manoj S, Koteswara M, Wishu S, Varma DP. Sensitive liquid chromatography-tandem mass spectrometry method for quantification of hydrohlorothiazide in human plasma. Biomed Chromatogr 2005;19:751-60. 9. Wankhede SB, Tajne MR, Gupta KR, Wadodkar SG. RPHPLC Method for simultaneous estimation of telmisartan and hydrochlorothiazide in tablet dosage form. Indian J Pharm Sci 2007;69:298-300. 10. Erk N. Simultaneous determination of irbesartan and hydrohlorothiazide in human plasma by liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2003;784:195-201. 11. Erk N. Simultaneous analysis of candesartan cilexetil and hydrohlorothiazide in human plasma and dosage forms using HPLC with photo diode array detector. J Liquid Chromatogr Relat Tech 2003;26:2581-91. TABLE 1: SYSTEM SUITABILITY TEST PARAMETERS FOR qUINAPRIL AND HYDROCHLOROTHIAZIDE BY PRPPOSED METHOD System suitability Parameters Results Quinapril Hydrochlorothiazide Theoretical plates 8837 6551 Resolution 3.31 Linearity (μg/ml) 30-150 40-200 Correlation coefficient 0.9946 0.9953 % Recovery 98.78 99.38 LOD (μg/ml) 0.05 0.02 LOQ (μg/ml) 0.4 0.1 Tailing factor 1.13 1.09