Simultaneous Determination Of Atorvastatin Research Articles

Continuous Wavelet Transform for Simultaneous Determination of Atorvastatin and Rosuvastatin in Combined Pharmaceutical Formulations

Continuous Wavelet Transform for Simultaneous Determination of Atorvastatin and Rosuvastatin in Combined Pharmaceutical Formulations

Development of Dioctyl Phthalate@Fe3O4 Nanocomposite Reinforced Hollow Fiber Solid/ Liquid Phase Microextraction Followed by HPLC-DAD for the Determination of Atorvastatin and Gemfibrozil in Human Urine.

The desirable levels of lipids, especially in patients with coronary artery disease, might not be achievable with a single lipid-lowering drug; thus, combination therapy using atorvastatin and gemfibrozil seems to be a promising approach. However, the potential for drugdrug interaction needs to be taken into consideration, and the combination (atorvastatin and gemfibrozil) is recommended only when other options for reducing lipids have been exhausted. Many studies are conducted for the determination of atorvastatin or gemfibrozil in biological fluids and tablets; however, the simultaneous determination of the two drugs in complex biological matrices is limited. Consequently, the development of a sensitive method for simultaneous determination of atorvastatin and gemfibrozil in urine samples is urgently needed to make sure that the doses of both medications are given to patients correctly to prevent the risk of side effects outcomes associated with the adverse drug-drug interaction. A synthesized nanocomposite sorbent, dioctyl phthalate coated on the surface of magnetite (DOP@Fe3O4), was reinforced and immobilized into the pores of 2.5 cm segment hollow fiber microtube via ultrasonication, and the lumen of the microtube was filled with 1-octanol as an organic solvent with two ends heat-sealed. The prepared (DOP@Fe3O4-HF-SLPME) device was directly immersed into 10 mL of a sample solution containing atorvastatin and gemfibrozil with agitation. Subsequently, the microextraction device was transferred to HPLC-micro-vial containing an appropriate solvent, and the selected analytes were desorbed under ultrasonication prior to HPLCDAD analysis. The main factors influencing the adsorption and desorption process of the selected drugs have been optimized. The DOP@Fe3O4-HF-SLPME combined with the HPLC-DAD method was analytically evaluated for the simultaneous determination of atorvastatin and gemfibrozil in human urine samples using the optimized conditions. In spiked urine samples, the method showed a good linearity R2˃ 0.998, RSD from 1.41- 5.33%, and the limits of detection/ quantification (LOD/ LOQ) were 0.11/ 0.36 and 0.73/ 2.42 μg L-1 for atorvastatin and gemfibrozil, respectively. The enrichment factors of atorvastatin and gemfibrozil were 83.4 and 101.2, with extraction recoveries of 80.9% and 99.0%, respectively. The developed method demonstrated comparable results against referenced methods and a satisfactory result for determining the selected drugs in the patient's urine samples. The DOP@Fe3O4-HF-SLPME followed by HPLC-DAD was proved to be an efficient, sensitive, and cost-effective biopharmaceutical analysis method for trace levels of atorvastatin and gemfibrozil in the biological fluid matrix.

Chemometric Simultaneous Determination of Atorvastatin and Amlodipine in Bulk and Tablets

A simple, accurate and precise UV-spectrophotometric method based inverse least-squares was developed for the simultaneous determination of atorvastatin and amlodipine in tablet formulation. The absorbance values of the two analytes were linear with the concentration at the wavelengths taken at 5 nm interval over the range of 230 -260 nm. The calibration equations were developed using the absorbance values of nine synthetic mixtures containing different concentrations of two analytes measured at 5 nm intervalsin the range of 230 -260 nm. The developed equations werethen validated by calculating the analytes recovery from the analysis of a set of another five synthetic mixtures, the mean% recoveries were 100.02% and 100.06% with the corresponding% RSD of ±0.36 and±0.51 for atorvastatin and amlodipine, respectively. The calibration equations obtained were then used to obtain the concentration of each analyte in commercial samples. The mean % recoveries were 100.43% and 100.28% with the corresponding% RSD of ±0.78 and±0.85 for atorvastatin and amlodipine, respectively. The validity of the proposed method was confirmed through the statistical comparison of the obtained results with those obtained by a reference method utilizing high performance liquid chromatography for the determination of the two actives, the calculated t-values at (P=0.05, n =6) were 1.47 and 0.73 compared to the tabulated value of 2.23.

Stability indicating RP-UPLC method for the simultaneous determination of Atorvastatin and Amlodipine

Amlodipine is a calcium channel blocker. Atorvastatin is used for lowering the cholesterol. A new stability indicating liquid chromatographic method (RP-UPLC) has been proposed for the simultaneous estimation of Atorvastatin and Atorvastatin. Acquity UPLC HSS C18 column was used for the chromatographic study and a mobile phase mixture consisting of 0.1% Formic acid: Acetonitrile: Methanol (0.1:45: 55, v/v)/ 0.3/220 (Flow rate: 0.3 mL/min) (PDA detector 220 nm) was used for the elution of these two drugs. Stress degradation studies were performed and the method was validated as per ICH guidelines.

Simultaneous determination of atorvastatin and its metabolites in human plasma by UPLC-MS/MS

A rapid, sensitive and selective ultra-performance liquid chromatography mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of atorvastatin and all its as-yet-identified metabolites in human plasma.

Application of Multivariate Calibration Methods, in Dissolution Testing and Simultaneous Determination of Atorvastatin and Ezetimibe in Their Combined Solid Dosage Form

Background: Two simple, precise and accurate multivariate calibration methods, partial least square (PLS) and principal component regression (PCR) have been applied for the simultaneous determination and dissolution profile evaluation of atorvastatin (ATV) and ezetimibe (EZT) in their binary mixtures and commercial tablets. Due to the closely overlapping spectral bands of the mentioned drugs, simultaneous determination without previous separation is not possible by conventional spectrophotometric methods. In the proposed methods (PLS and PCR) determination of chemicals was performed by the use of a full-spectrum multivariate calibration method. Methods: The experimental calibration matrix was designed orthogonally with 16 samples composed of different mixtures of both compounds in related mediums. The simultaneous determination of ATV and EZT was accomplished in mixtures through recording the absorption spectra within a range of 210 to 300 nm. Results: The concentration of ATV and EZT were considered in the linear range, between 8 to 14 µg.ml-1. The specificity of the methods was evaluated by analyzing laboratory prepared mixtures of the mentioned drugs in specific proportions. Conclusion: The applied methods were successfully employed in simultaneous spectrophotometric determination and dissolution profile evaluation of ATV and EZT in their prepared mixtures and pharmaceutical formulation.

Simultaneous determination of atorvastatin and valsartan in human plasma by solid-based disperser liquid-liquid microextraction followed by high-performance liquid chromatography-diode array detection.

A simple, sensitive, and efficient method has been developed for simultaneous estimation of valsartan and atorvastatin in human plasma by combination of solid-based dispersive liquid-liquid microextraction and high performance liquid chromatography-diode array detection. In the proposed method, 1,2-dibromoethane (extraction solvent) is added on a sugar cube (as a solid disperser) and it is introduced into plasma sample containing the analytes. After manual shaking and centrifugation, the resultant sedimented phase is subjected to back extraction into a small volume of sodium hydrogen carbonate solution using air-assisted liquid-liquid microextraction. Then the cloudy solution is centrifuged and the obtained aqueous phase is transferred into a microtube and analyzed by the separation system. Under the optimal conditions, extraction recoveries are obtained in the range of 81-90%. Calibration curves plotted in drug-free plasma sample are linear in the ranges of 5-5000μgL(-1) for valsartan and 10-5000μgL(-1) for atorvastatin with the coefficients of determination higher than 0.997. Limits of detection and quantification of the studied analytes in plasma sample are 0.30-2.6 and 1.0-8.2μgL(-1), respectively. Intra-day (n=6) and inter-days (n=4) precisions of the method are satisfactory with relative standard deviations less than 7.4% (at three levels of 10, 500, and 2000μgL(-1), each analyte). These data suggest that the method can be successfully applied to determine trace amounts of valsartan and atorvastatin in human plasma samples.

An Improved HPLC Method with the Aid of a Chemometric Protocol: Simultaneous Determination of Atorvastatin and Its Metabolites in Plasma

The aim of the present study was to optimize a chromatographic method for the analysis of atorvastatin (acid and lactone forms), ortho- and para-hydroxyatorvastatin by using an experimental design approach. Optimization experiments were conducted through a process of screening and optimization. The purpose of a screening design is to identify the factors that have significant effects on the selected chromatographic responses, and for this purpose a full 23 factorial design was used. The location of the true optimum was established by applying Derringer’s desirability function, which provides simultaneously optimization of all seven responses. The ranges of the independent variables used for the optimization were content of acetonitrile in mobile phase (60–70%), temperature of column (30–40 °C) and flow rate (0.8–1.2 mL min−1). The influences of these independent variables were evaluated for the output responses: retention time of first peak (p-hydroxyatorvastatin) and of last peak (atorvastatin, lactone form), symmetries of all four peaks and relative retention time of p-hydroxyatorvastatin. The primary goal of this investigation was establishing a new simple and sensitive method that could be used in analysis of biological samples. The method was validated and successfully applied for determination of atorvastatin (acid and lactone forms) and its metabolites in plasma.

Solving matrix effect, spectral overlapping and nonlinearity by generalized standard addition method coupled with radial basis functions–partial least squares: simultaneous determination of atorvastatin and amlodipine in urine

For simultaneous determination in conditions with spectral overlap and variation of matrix effects, coupling of the generalized standard addition method (GSAM) with the multivariate nonlinear method of radial basis function–partial least squares (RBF–PLS) was proposed. The nonlinearity caused by the GSAM used to correct matrix effects was studied, and principal component analysis was proposed for identifying it. In the method introduced, the whole sensor range can be used without the collinearity problem encountered in the application of GSAM with classical least squares (CLS), and calibration can be made for each analyte, separately. The introduced method was applied to determine amlodipine and atorvastatin in urine samples. The mean of the percent recoveries was between 95 and 101.12. The percent relative standard deviation values of the method were in most cases below 5%. The results of GSAM–RBF–PLS were compared with those obtained by GSAM–CLS and GSAM–PLS. Copyright © 2013 John Wiley & Sons, Ltd.

Simultaneous determination of atorvastatin, metformin and glimepiride in human plasma by LC–MS/MS and its application to a human pharmacokinetic study

A simple, rapid and sensitive liquid chromatography-tandem mass spectrometric (LC–MS/MS) assay method has been developed and fully validated for the simultaneous quantification of atorvastatin, metformin and glimepiride in human plasma. Carbamazepine was used as internal standard (IS). The analytes were extracted from 200μL aliquots of human plasma via protein precipitation using acetonitrile. The reconstituted samples were chromatographed on a Alltima HP C18 column by using a 60:40 (v/v) mixture of acetonitrile and 10mM ammonium acetate (pH 3.0) as the mobile phase at a flow rate of 1.1mL/min. The calibration curves obtained were linear (r2≥0.99) over the concentration range of 0.50–150.03ng/mL for atorvastatin, 12.14–1207.50ng/mL for metformin and 4.98–494.29ng/mL for glimepiride. The API-4000 LC–MS/MS in multiple reaction monitoring (MRM) mode was used for detection. The results of the intra- and inter-day precision and accuracy studies were well within the acceptable limits. All the analytes were found to be stable in a battery of stability studies. The method is precise and sensitive enough for its intended purpose. A run time of 2.5min for each sample made it possible to analyze more than 300 plasma samples per day. The developed assay method was successfully applied to a pharmacokinetic study in human male volunteers.

Simultaneous determination of atorvastatin and niacin in human plasma by LC‐MS/MS and its application to a human pharmacokinetic study

A rapid, simple, sensitive and selective LC-MS/MS method has been developed and validated for quantification of the atorvastatin (AT) and niacin (NA) in 250 μL human plasma. The analytical procedure involves a liquid-liquid extraction method using nevirapine as an internal standard (IS). The chromatographic separation was achieved on a Hypurity Advance (4.6 × 50 mm, 5 µm) column using a mobile phase consisting of 0.1% formic acid buffer-acetonitrile (20:80, v/v) at flow rate of 0.8 mL/min. The API-4000 LC-MS/MS was operated in the multiple-reaction monitoring mode using electrospray ionization. The total run time of analysis was 3 min and elution of AT, NA and IS occurred at 1.06, 1.84 and 0.92 min, respectively. A detailed validation of the method was performed as per the US Food and Drug Administration guidelines and the standard curves found to be linear in the range of 0.10-30.0 ng/mL for AT and 20.2-6026 ng/mL for NA, with a coefficient of correlation of ≥ 0.99 for both the compounds. AT and NA were found to be stable in a battery of stability studies, viz. bench-top, autosampler, re-injection, wet-extract and repeated freeze-thaw cycles. The developed assay method was successfully applied to a pharmacokinetic study in humans.

Simultaneous Determination of Atorvastatin and Aspirin in Human Plasma by LC–MS/MS: Its Pharmacokinetic Application

A simple, rapid, and sensitive liquid chromatography tandem mass spectro-metric (LC–MS/MS) assay method has been developed and fully validated for the simultaneous quantification of atorvastatin and aspirin in human plasma using a polarity switch. Proguanil and furosemide were used as the internal standards for the quantification of atorvastatin and aspirin, respectively. The analytes were extracted from human plasma by the liquid–liquid extraction technique using methyl tert-butyl ether. The reconstituted samples were chromatographed on a Zorbax XDB Phenyl column by using a mixture of 0.2% acetic acid buffer, methanol, and acetonitrile (20:16:64, v/v) as the mobile phase at a flow rate of 0.8 mL/min. Prior to detection, atorvastatin and aspirin were ionized using an ESI source in the multiple reaction monitoring (MRM) mode. The ions were monitored at the positive m/z 559.2→440.0 transition for atorvastatin and the negative m/z 179.0→136.6 transition for aspirin. The calibration curve obtained was linear (r2 ≥ 0.99) over the concentration range of 0.20–151 ng/mL for atorvastatin and 15.0–3000 ng/mL for aspirin. The method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 3.0 min for each sample made it possible to analyze more than 300 human plasma samples per day. The proposed method was found to be applicable to clinical studies.

Simultaneous Determination of Atorvastatin and Glimepiride by LC-MS/MS in Human Plasma and Its Application to a Pharmacokinetic Study

The aim of the proposed research work was to develop and validate a simple, selective high sensitive and high-throughput assay for the simultaneous estimation of Atorvastatin and Glimepiride in human plasma using liquid chromatography tandem mass spectrometry (LC-MS/MS). Atorvastatin–Glimepiride combines a competitive inhibitor of HMG-CoA reductase and a sulfonylurea anti-diabetic drug. The purpose of this study was to develop single method for Atorvastatin and Glimepiride in plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) that would result into a simultaneous estimation of Atorvastatin and Glimepiride avoiding acid –lactone inter conversions right from sample collections to analysis on the LC-MS/MS. Sample collection procedure optimized for Atorvastatin holds good for Glimepiride, hence resulting into a simultaneous estimation of Atorvastatin and Glimepiride. Liquid-liquid extraction and liquid chromatography coupled to positive ion mode tandem mass spectrometry was used to develop the method and was validated according to US FDA guidelines. The calibration curves for two analytes were linear (R2 ≥ 0.9950, n = 4) over the concentration range of 0.2 - 30 ng/mL for Atorvastatin and 1 - 250 ng/mL for Glimepiride. Mean extraction recoveries 80.34 ± 9.43 for Atorvastatin and 88.19 ± 7.13 for Glimepiride. Intra- and inter-run mean percent accuracy was between 85% - 115% and percent imprecision was ≤15%. Stability studies revealed that Atorvastatin and Glimepiride were stable in plasma during bench top (10.5 h at room temperature), in Injector (47.5 h), at the end of three successive freeze and thaw cycles and long term at -65℃ ± 15℃ for 114 days. The method was successfully applied to the study of pharmacokinetics of Atorvastatin and Glimepiride in healthy volunteers. Simultaneous estimation of Atorvastatin and Glimepiride is cost effective, reduces analysis cycle time, enables effective utilization of resources and reduces bleeding burden on human volunteers.

Simultaneous determination of atorvastatin, amlodipine, ramipril and benazepril in human plasma by LC‐MS/MS and its application to a human pharmacokinetic study

A rapid, simple, sensitive and specific LC-MS/MS method has been developed and validated for the simultaneous estimation of atorvastatin (ATO), amlodipine (AML), ramipril (RAM) and benazepril (BEN) using nevirapine as an internal standard (IS). The API-4000 LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. Analytes and IS were extracted from plasma by simple liquid-liquid extraction technique using ethyl acetate. The reconstituted samples were chromatographed on C(18) column by pumping 0.1% formic acid-acetonitrile (15:85, v/v) at a flow rate of 1 mL/min. A detailed validation of the method was performed as per the FDA guidelines and the standard curves were found to be linear in the range of 0.26-210 ng/mL for ATO; 0.05-20.5 ng/mL for AML; 0.25-208 ng/mL for RAM and 0.74-607 ng/mL for BEN with mean correlation coefficient of ≥0.99 for each analyte. The intra-day and inter-day precision and accuracy results were well with in the acceptable limits. A run time of 2.5 min for each sample made it possible to analyze more than 400 human plasma samples per day. The developed assay method was successfully applied to a pharmacokinetic study in human male volunteers.

Spectrophotometric determination of atorvastatin and amlodipine by H-point standard addition method with simultaneous addition of both analytes in nonaqueous solution

H-point standard addition method(HPSAM) with simultaneous addition of both analytes in nonaqueous solution was applied for determination of Atorvastatin (AT) and Amlodipine (AML). The results showed that simultaneous determination could be performed with the ratio 0.16 to 4.3 of AT–AML. The corresponding values of LOD were obtained for AT and AML 1.2 × 10–6 and 9 × 10–7 mol l–1, respectively, and the corresponding values of LOQ were obtained for AT and AML 4 × 10–6 and 3 × 10–6 mol l–1, respectively. Underworking conditions, the proposed method was successfully applied for simultaneous determination of AT and AML in several synthetic mixtures and Amostatine tablets.

Validated Ultra HPLC Method for the Simultaneous Determination of Atorvastatin, Aspirin, and their Degradation Products in Capsules

An Ultra HPLC method was developed and validated for the simultaneous determination of atorvastatin, aspirin, and their major degradation products in capsules. Salicylic acid, acetylsalicylsalicylic acid, salicylsalicylic acid, and the lactone form of atorvastatin were separated along with six unknown degradation products within 4 min. The chromatographic separation was performed on acquity UPLCTM BEH C18 column (1.7 µm, 2.1 × 50 mm); using a gradient elution of acetonitrile and phosphate buffer (0.01 M, pH 2.0) at a flow rate of 0.6 mL/min. UV detection was performed at 247 nm. The method was validated for accuracy, repeatability, reproducibility, and robustness. Stability indicating capability was established by forced degradation experiments and separation of known degradation products. Linearity, LOD, and LOQ was established for atorvastatin, aspirin, and their known degradation products.

RP-HPLC method for the simultaneous determination of Atorvastatin and Amlodipine in tablet dosage form

A simple, precise, accurate, and rapid HPLC method has been developed, and validated for the determination of atorvastatin and amlodipine simultaneously, in combined tablet dosage form. The mobile phase used was a mixture of acetonitrile and 0.03M phosphate buffer pH 2.9 (55:45% v/v). The detection of atorvastatin and amlodipine was carried out on dual g absorbance detector at 240 nm and 362 nm, respectively. Results of the analysis were validated statistically, and by recovery studies. The proposed method can be successfully used to determine the drug contents of marketed formulation.