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Title of Thesis
Development and Validation of Liquid Chromatographic Methods for Anti- Hyperlipidemic Drugs in Binary Combinations

Author(s)
Muhammad Ashfaq
Institute/University/Department Details
GC University, Lahore, Pakistan
Session
2009
Subject
Chemistry
Number of Pages
208
Keywords (Extracted from title, table of contents and abstract of thesis)
Atorvastatin- Ezetimibe, Ezetimibe-Simvastatin, Gemfibrozil-Simvastatin, Ezetimibe-Fenofibrate Ezetimibe-Lovastatin, Atorvastatin-Gemfibrozil, Rosuvastatin-Ezetimibe dua.

Abstract
In the present dissertation, stress was applied to determine anti-hyperlipidemic drugs in combination form especially in binary combinations using simple, sensitive and economic HPLC methods. Seven HPLC methods have been developed for Atorvastatin- Ezetimibe, Ezetimibe-Simvastatin, Gemfibrozil-Simvastatin, Ezetimibe-Fenofibrate Ezetimibe-Lovastatin, Atorvastatin-Gemfibrozil and Rosuvastatin-Ezetimibe dua formulations. The first HPLC method was developed for the simultaneous determination of atorvastatin and ezetimibe in tablet formulations. Chromatographic separation was achieved on a 250 4.6 mm, 5μ Hypersil phenyl-2 column at 242 nm using a mixture of 0.1 M ammonium acetate (pH 6.5) and acetonitrile in the ratio of 28:72 (v/v) as a mobile phase. The method was linear in the concentration range of 12 52 μg/ml for both atorvastatin and ezetimibe with correlation coefficient between 0.9966 and 0.9993. The total run time was less than 5 min. The second method which was developed was for the simultaneous determination of ezetimibe and simvastatin in pharmaceutical formulations. Chromatographic separation was performed on a Merck C18 column at a wavelength of 240 nm using a mixture of 0.1M ammonium acetate buffer pH 5.0 and acetonitrile in the ratio of (30:70, v/v . The method results in excellent separation with good resolution between the two analytes. The within day variation was between 0.28 and 1.10 % and between day variation was between 0.56 and 1.32 %. The recovery was greater than 99.12 % with RSD less than 1.38 %. In the third method, conditions were optimized to develop a simple, sensitive and validated HPLC method to determine gemfibrozil and simvastatin simultaneously in synthetic mixture form. Chromatographic separation was achieved on a C-18 column using a mixture of 0.1 M ammonium acetate pH 5.0 and acetonitrile in the ratio of 15:85 (v/v) at a wavelength of 237 nm. Linearity of the method was found to be in the concentration range of 60-420 μg/ml for gemfibrozil and 1-7 μg/ml for simvastatin with correlation coefficient greater than 0.9999. The fourth method developed for available binary combination was the simultaneous ABSTRACT ii determination of ezetimibe and fenofibrate in tablets. Isocratic chromatography was performed on a Merck C-18 column using a mixture of 0.1 M ammonium acetate pH 5.0 and acetonitrile in the ratio of (25:75, v/v) at a flow rate of 1.5 ml/min. The detection was carried out at a wavelength of 240 nm using a photodiode array detector. The method was linear in the concentration range of 0.8-40 μg/ml for ezetimibe and 12.8-640 μg/ml for fenofibrate. The fifth method developed was for the simultaneous determination of ezetimibe and lovastatin in synthetic mixture form. Chromatographic separation was performed on a C- 18 column using a mixture of 0.1M ammonium acetate buffer pH 5.0 and acetonitrile in the ratio of (28:72, v/v). The detection was carried out at a wavelength of 240 nm using a photodiode array detector. The method was linear in the concentration range of 0.2-100 μg/ml for ezetimibe and 0.4-200 μg/ml for lovastatin. The within day variation was between 0.32 and 1.22 % and between day variation was between 0.98 and 1.63 %. The recovery was greater than 102 % with RSD less than 1.5 %. Later the method was also applied for the determination of these two drugs in spiked human plasma. No plasma peaks interfered with the peaks of active anaytes, which means it can also be used for the determination in human plasma. The separation procedure for the simultaneous determination of atorvastatin and gemfibrozil in synthetic mixture form was also developed. Chromatographic separation was achieved on a C-18 column using a mixture of 0.1 M ammonium acetate pH 5.0 and acetonitrile in the ratio of 45:55 (v/v) at a wavelength of 240 nm. Linearity of the method was found to be in the concentration range of 0.1-20 μg/ml for atorvastatin and 6-1200 μg/ml for gemfibrozil with correlation coefficient 0.9997 for atorvastatin and 0.9976 for gemfibrozil. The elution time for the two components was less than twelve minutes. Forced degradation study was also applied to both the drugs individually and in combination form. During the forced degradation study under oxidative stress, a novel degradation product was also isolated in crystalline form. Later the developed method under the same chromatographic conditions was also applied for the determination of these two drugs in spiked human plasma. No plasma peaks interfered with the peaks of active anaytes, which means it can also be used for the determination in human plasma. ABSTRACT iii The pair for the simultaneous quantification of rosuvastatin and ezetimibe was also proceeded. Chromatographic separation was performed on a C18 column at a wavelength of 240 nm using a mixture of 1% phosphoric acid solution and acetonitrile in the ratio of (40:60, v/v). The method was linear in the concentration range of 0.8 to 160 μg/ml for rosuvastatin and 0.2 to 40 μg/ml for ezetimibe with correlation coefficient equal to 0.9993 for rosuvastatin and 0.9996 for ezetimibe. The within day precision was between 0.95 and 1.51 % and between day precision was between 1.28 and 2.05 %. All the developed methods were validated in terms of linearity, accuracy, recovery, precision, robustness, specificity and LOD/LOQ values. The total eluting time for every method was less than twelve minutes. The results obtained for each method indicate that they can be reliably used for the simultaneous determination of dual components present in each study.

 
         
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2300 KB

S. No. Chapter Title of the Chapters Page Size (KB)
1 1 Introduction 1  

 

 


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  1.1 What is Hyperlipidemia? 1
  1.2 Causes of hyperlipidemia 1
  1.3 Symptoms and diagnoses of Hyperlipidemia 2
  1.4 Classes of Lipoprotein 3
  1.5 Classification of hyperlipidemia 4
  1.6 Classification of Antihyperlipidemic Drugs 6
  1.7 Combination therapy for Hyperlipidemia 12
  1.8 Antihyperlipidemic Drugs 16
  1.9 High Performance Liquid Chromatography (HPLC) 26
  1.10 Quantitative Analysis 28
  1.11 Statistics 30
  1.12 Manufacturing Process of Tablet Dosage form 32
  1.13 Aims and objective of the research work 34
2 2 Literature Survey 35  


213 KB

  2.1 Analytical Methods for Atorvastatin 35
  2.2 Analytical Methods for Simvas 41
  2.3 Analytical Methods for Lovastatin 46
  2.4 Analytical Methods for Rosuvastatin 50
  2.5 Analytical Methods for Gemfibrozil 52
  2.6 Analytical Methods for Fenofibrate 55
  2.7 Analytical Methods for Ezetimibe 59
3 3 Experimental Work 63  

 


211 KB

  3.1 Solvents 63
  3.2 Chemicals 63
  3.3 Analytical equipments 64
  3.4 Glass Apparatus 64
  3.5 Atorvastatin calcium and Ezetimibe 66
  3.6 Ezetimibe and Simvastatin 70
  3.7 Gemfibrozil and Simvastatin 74
  3.8 Ezetimibe and Fenofibrate 77
  3.9 Ezetimibe and Lovastatin 81
  3.10 Atorvastatin and Gemfibrozil 85
  3.11 Rosuvastatin and Ezetimibe 89
4 4 Results and Discussion 93  


861 KB

  4.1 Atorvastatin calcium and Ezetimibe 93
  4.2 Ezetimibe and Simvastatin 103
  4.3 Gemfibrozil and Simvastatin 112
  4.4 Ezetimibe and Fenofibrate 122
  4.5 Ezetimibe and Lovastatin 132
  4.6 Atorvastatin and Gemfibrozil 142
  4.7 Rosuvastatin and Ezetimibe 153
  4.8 Conclusion 163
5 5 References 165
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