Simultaneous estimation

A new, simple, rapid, selective, precise and accurate isocratic reverse phase high performance liquid Chromatography assay method has been developed for simultaneous estimation of Isoniazid and Pyridoxine tablet formulations. The separation was achieved by using column Hypersil BDS, (250 x 4.6 mm, 5 µ) (Make: Thermo), in mobile phase consisted of pH4.0 phosphate buffer and Acetonitrile in the ratio of 75:25 v/v. The flow rate was 1.0 mL/min, column oven temperature 30° C, the injection volume was 10 μL, and detection was performed at 267 nm using a photodiode array detector (PDA), Run time 6 minutes. The retention time of Isoniazid and Pyridoxine, was noted to be 3.5 minutes and 4.3 minutes respectively, indicative of rather shorter analysis time. The method was validated as per ICH guidelines. The proposed method was found to be accurate, reproducible, and consistent.

A new simple, accurate, rapid and precise isocratic RP-HPLC was developed and validated for the determination of Rosuvastatin and Ezetimibe in Pharmaceutical tablet dosage form by droping method. The Method employs Shimadzu LC system on Hypersil ODS column (4.6 x 250 mm, 5 µm) and flow rate of 1.5ml/min with an injection volume 20µl.  Buffer, Acetonitrile and Methanol was used as mobile phase in the composition of 40:30:30v/v. The Detection was carried out at 230nm. Linearity ranges for Rosuvastatin and Ezetimibe were 11-33µg/ml, 10-30µg/ml respectively for HPLC. Retention Time of Rosuvastatin and Ezetimibe were found to be 3.7 and 5.7 min respectively. Percent Recovery study values of Rosuvastatin and Ezetimibe were found 99.6-101.1% and 99.9-100.7% respectively. This newly developed method i.e. droping method was successfully utilized for the Quantitative estimation of Rosuvastatin and Ezetimibe in tablet dosage form. This method was validated for selectivity, accuracy, precision, and linearity, Ruggedness, Robustness and Stability Studies as per ICH guidelines.

A simple, precise and accurate stability indicating RP-HPLC method has been developed and subsequently validated for the simultaneous estimation of Sildenafil citrate and Estradiol valerate in bulk and pharmaceutical formulation. The separation was carried out using C18 column (150mm x 4.6mm, 5μm), mixture of acetonitrile and water 80:20 % v/v as a mobile phase with a flow rate of 1 ml/min and the effluent was monitored at 290 nm using PDA detector. The retention time of Sildenafil citrate and Estradiol valerate were 2.55 min and 5.56 min respectively. The method is linear over the range of 125 - 750 μg/ml and 5 - 30 μg/ml for Sildenafil citrate and Estradiol valerate respectively. The method was found to be precise, accurate and specific during the study. The percentage assay was found to be 100.68 % and 99.58 % for Sildenafil citrate and Estradiol valerate respectively from the tablet formulation. Sildenafil citrate and Estradiol valerate were subjected to stress condition to check the degradation behaviour of them. The drugs undergo degradation under acidic, basic, oxidative and thermal condition. The proposed method enables rapid quantification and simultaneous analysis of both drugs from commercial formulations without any interference of excipients. So, the method can be used for routine analysis of Sildenafil citrate and Estradiol valerate in combined tablet formulation.

A simple, accurate, precise and stability-indicating RP-HPLC method has been developed and validated for the simultaneous estimation of Telmisartan and Chlorthalidone in fixed-dosage formulation. The separation was achieved on a octadecyl C-18 reversed phase column (Symmetry C-18, 250mm x 4.6mm , 5µ) using acetonitrile:phosphate buffer at pH 6.5 (70:30 v/v) as mobile phase at a flow rate of 1.0mL/min and temperature of 25°C. The UV detection was carried out at 270nm. The retention time of Chlorthalidone and Telmisartan was found to be 5.48 and 13.38 min. respectively. The method has been validated for Specificity, Linearity, Accuracy, Precision and Robustness. The calibration curve for Chlorthalidone and Telmisartan were linear from the range of 1.25-20.01 µg/mL and 8.0 to 128.4 µg/mL respectively. The mean recoveries obtained for Telmisartan and Chlorthalidone were 100.9% and 99.7% respectively. The developed method was found to be Specific, accurate, Precise, Robust and rapid for the simultaneous estimation of Telmisartan and Chlorthalidone in Telmisartan and Chlorthalidone Tablets 80mg/12.5mg.

A new, simple, accurate, precise and reproducible RP-HPLC method for the simultaneous estimation of Sitagliptin Phosphate Monohydrate and Simvastatin has been developed and validated. Chromatographic separation was achieved using Neosphere C-18 column (4.6 mm 250mm,5mm) in gradient mode with a mobile phase consisting a mixture of acetonitrile:methanol:0.1% orthophosphoric acid in water (70:15:15v/v) at a flow rate of 1ml/min. The eluents were detected at 254 nm using UV detector. The retention time of Sitagliptin Phosphate Monohydrate and Simvastatin were found to be 2.09min and 7.79min respectively. The method was linear over the concentration range of 25-150μg/mL for Sitagliptin Phosphate Monohydrate and 10-60μg/mL for Simvastatin. The % recoveries for Sitagliptin Phosphate Monohydrate and Simvastatin were found to be 98.98-101.06% and 99.89-102.43% respectively. The developed method was validated for parameters like system suitability, specificity, linearity, accuracy, precision, ruggedness and robustness as per International Conference on Harmonization guidelines and the results were found to be within the limits. This validated method can be used for the routine quality control analysis of Sitagliptin Phosphate Monohydrate and Simvastatin in combined dosage form.

A new rapid, precise and sensitive reverse phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the estimation of Atazanavir and Ritonavir simultaneously in combined dosage form. The two components Atazanavir and Ritonavir were well resolved on an isocratic method, C18 column, utilizing a mobile phase composition of acetonitrile: 0.02M ammonium acetate buffer (40:60), v/v, pH 4.0) at a flow rate of 1.0 mL/min with UV detection at 205 nm. The retention time of Atazanavir and Ritonavir were 2.8 min and 5.7 min respectively. The developed method was validated for specificity, linearity, precision, accuracy, limit of detection (LOD), limit of quantification (LOQ) and robustness as per ICH guidelines. Linearity for Atazanavir and Ritonavir were found in the range of 18.0-42.0 µg/ml and 5.0-14.0 µg/ml, respectively. The percentage recoveries for Atazanavir and Ritonavir ranged from 98.9-101.0 % and 98.2-100.1 %, respectively. The proposed method could be used for routine analysis of Atazanavir and Ritonavir in their combined dosage forms.

A new RP – HPLC method was developed for the simultaneous determination of  Montelukast and Rupatadine fumerate in combined dosage form. An Inertsil C18 column(100 x 4.6, 5µm) was used with mobile phase of composition Methanol : Buffer(0.1% triethyl amine in water with pH adjusted to 3.0 (70:30v/v at pH 4.6) at a flow rate of 1.0 mL/min and injection volume of 20µL with UV detection at 266 nm for separating Montelukast and Rupatadine fumerate. The retention time of Rupatadine fumerate and Montelukast were 5.76 min and 2.86 min respectively. The runtime of the analysis was 6 minutes. The specificity, linearity, precision, accuracy, limit of detection (LOD), limit of quantification (LOQ), ruggedness and robustness of the developed method were studied to validate as per ICH guidelines. The Linearity range for Montelukast and Rupatadine fumerate were 5.0 – 30.0 µg/ml and 5.0 – 30.0 µg/ml, respectively. The percentage recoveries were in the range for Montelukast and Rupatadine fumerate98.80-100.11 % and 99.06-99.44 %, respectively. The developed  method could be used for routine analysis of Montelukast and Rupatadine fumeratein their combined dosage forms.

A new validated RP – HPLC method was developed for the simultaneous determination of Thiocolchicoside and Ketoprofen in combined dosage form. The method developed produced high sensitivity, precision and accuracy. An isocratic C18 (Inertsil ODS, 250 x 4.6 mm, 5µ) column was used with mobile phase of composition Acetonitrile: Phosphate buffer (70: 30 at pH 4.6) at a flow rate of 1.0 mL/min with UV detection at 258.2 nm for separating Thiocolchicoside and Ketoprofen. The retention time of Thiocolchicoside and Ketoprofen were 2.4 min and 3.5 min respectively. The developed method was validated for specificity, linearity, precision, accuracy, limit of detection (LOD), limit of quantification (LOQ) and robustness as per ICH guidelines. Linearity for Thiocolchicoside and Ketoprofen were found in the range of 2.0 – 12.0 µg/ml and 6.2-38.75 µg/ml, respectively. The percentage recoveries for Thiocolchicoside and Ketoprofen ranged from 99.35- 100.21% and 98.66-99.29 %, respectively. The proposed method could be used for routine analysis of Thiocolchicoside and Ketoprofen in their combined dosage forms. All the proposed methods for Thiocolchicoside and ketoprofenare simple, selective, reproducible and specific with good precision and accuracy. The method was proved to be superior to most of the reported methods. These proposed methods for estimation of selected drugs were successfully applied either in tablet dosage form. More over the low solvent consumption along with short retention time of 2.4 and 3.5 for both Thiocolchicoside and Ketoprofen to be cost effective when compared to other developed method shown in literature reviews. The proposed method can be used as alternative methods to the reported ones for the routine determination of selected drugs under the study in tablet dosage form

A simple, rapid, and precise RP-HPLC method for simultaneous analysis of Losartan potassium and Atorvastatin calcium in bulk and its pharmaceutical formulations has been developed and validated. Atorvastatin was separated from losartan by using Grace Smart Altima C-18 column (25 cm × 4.6 mm, 5-μm) with a mobile phase consisting of acetonitrile: 10mM phosphate buffer (55:45 %v/v, pH 3.0) a flow rate of 1mL/min and detection wavelength at 240 nm. Aceclofenac was used as an internal standard in this method. Losartan, atorvastatin and aceclofenac were eluted with retention times of 4.85 min, 8.31min and 9.51 min respectively. The method was validated for accuracy, precision, linearity and sensitivity in accordance with ICH (Q2B) guidelines and the results of all the validation parameters were found to be within the acceptable limits. The calibration plots were linear over the concentration ranges from 200-30000ng/mL (r2 = 0.999) for both the drugs. Accuracy and precision were determined by QC sample covering low, medium, and high concentration levels. Intra and inert-day accuracy were found to be 97.16-102.57% for losartan and 97.01-103.05% for atorvastatin. The limit of quantification was found to be166ng/mL and 179ng/mL for losartan and atorvastain respectively. The method was successfully applied for the assay of the dosage form, recovery of the individual drugs from the combined tablet dosage was found to be >97% for both the drugs. From the results it is suggested that the proposed method is simple, reproducible, accurate and precise.

A simple, economic and precise RP-HPLC method has been developed and validated for simultaneous estimation of thiocolchicoside (THC) and diclofenac (DCF) both in bulk drug and in capsule formulation. Reversed-phase chromatography was performed on a C18 Phenomenex-Gemini column with mobile phase acetonitrile: water (70:30 % v/v, adjusted at pH 3.0) at a flow rate of 1.0 ml/min. Detection was performed at 258 nm and sharp peaks were obtained for THC and DCF at a retention time of 1.537 min and 4.010 min respectively. The method was validated for accuracy, precision, detection and quantification limits, and system suitability in accordance with ICH guidelines. Linear regression analysis data for the calibration plot showed there was a linear relationship between response and concentration for THC in the range 4 - 24 μg/ml with the correlation coefficient 0.9998 and the linear regression equation y = 20.64x + 26.08. Linearity was observed in the range of 25 - 150 μg/ml with the correlation coefficient 0.9998 and the linear regression equation y = 11.13x + 65.27 for DCF. The detection (LOD) and quantification (LOQ) limits for THC were found to be 1.052 and 3.187 μg/ml and for DCF it was found to be 1.475 and 4.470 μg/ml. Statistical analysis proved that the method was precise, reproducible and accurate for simultaneous estimation of THC and DCF. The wide linearity range, sensitivity, accuracy, short retention time, and simple mobile phase imply that the method is suitable for routine quantification of THC and DCF with high precision and accuracy.