RP-HPLC

A simple, specific, accurate and precise reverse phase high performance liquid chromatographic (RP-HPLC) method was developed with high sensitivity for determination of Valsartan and Hydrochlorothiazide drugs in combined dosage forms. The separation was achieved on Zorbax CN (25 cm x 4.6 mm, 5 µm) at flow rate of 1.8 ml/min with 70: 30 mixture of phosphate buffer: acetonitrile (pH 6) as the mobile phase. The quantification was achieved with PDA detector at 265 nm. The injection volume was 20 μl. The retention times of Valsartan and Hydrochlorothiazide were 6.04 min and 2.27 min, respectively. The method was validated for linearity, precision, specificity, robustness and recovery according to the ICH guidelines. The linearity of response for Valsartan and Hydrochlorothiazide were assessed by analysis of five independent levels of calibration curve in range of 20-100 µg/ml and 2-10 µg/ml respectively. The recovery data was between 98.77-99.73% and 98.75-100.56% for Valsartan and Hydrochlorothiazide respectively. The limit of detection and quantification for Valsartan were 0.98 and 2.97μg/ml respectively and for Hydrochlorothiazide were 0.18 and 0.57μg/ml, respectively. The method was found to be simple and highly sensitive and can be useful in the routine quality control of Valsartan and Hydrochlorothiazide in bulk manufacturing and pharmaceutical dosage forms.

A simple isocratic RP-HPLC method was developed for the estimation of Lurasidone in bulk and pharmaceutical dosage forms by using Waters (Alliance) HPLC (2695 series) System operated with Empower software-2. The optimized chromatographic conditions were found to be buffer of 0.05% Trifluroacetic acid in 0.01 M Potassium dihydrogen orthophosphate solution, mobile phase of buffer and acetonitrile in the ratio 60: 40, Inertsil ODS, C18, 150mm x 4.6mm, 5µ particle size HPLC column at temperature of 30°C, 20 µL of injection volume, 1.0ml/min flow rate and UV detector with detection wavelength 231nm. Retention time and peak area of standard or sample were found to be 5.428min or 5.431 min. and 4128545 or 4126122 respectively. System precision and method precision were found to be less than 2.0%. The method was found to be linear within the limits 2.5-15.0µg/ml with good correlation coefficient 0.9999. The percent of recovery (accuracy) was found from 99.34 to 99.97%. Ruggedness and robustness studies were carried out and the results were found to be satisfactory. Stability of Lurasidone was studied under the different stressed conditions and found to be stable (96.37-93.55%). The % of assay of different dosage of Latuda tablets was found between 99.68 -100.18%. The proposed method was found to be sensitive, precise, accurate, linear, rugged and robust, and applied for the analysis of pharmaceutical formulations and percent of assay was evaluated, hence the proposed method can adopt for the routine analysis in any quality control laboratory.

RP-HPLC method has been developed for the quantitative estimation of Propranolol hydrochloride and Etizolam using C 18 column and a mobile phase consisting of Methanol and Water in the ratio 70:30. The mobile phase was pumped at a rate of 1ml/min and detection was carried out at 281.5 nm(iso-absorptive point). The linearity was found to be in range of 5-50µg/ml and 0.5-5µg/ml with regression coefficient (r2=0.999, and r2=0.997) for Propranolol hydrochloride and Etizolam respectively. The peaks obtained were sharp having baseline separation with a retention time of 2.35and 6.57min for Propranolol hydrochloride and Etizolam respectively.The LOD was found to be at the concentration of0.1µg/ml and 0.025µg/ml for Propranolol hydrochloride and Etizolam respectively. The percentage recovery was found to be 98.5% to 100.58% for Propranololhydrochloride and 95% to 106.6% for Etizolam. The method was validated statistically.

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 simple, rapid, sensitive, reversed phase-HPLC method was developed and validated to measure simultaneously the amount of Metformin and Vildagliptin at single wavelength (210 nm) in order to assess quantification in its tablet formulation and its subsequent stability studies. An isocratic elution of filtered sample was performed on Hypercil BDS C18 column with buffered mobile phase (0.1 M potassium dihydrogen ortho Phosphate buffer (Ph 4.8) and acetonitrile in the ratio of 60:40 v/v) with Hypercil BDS detection at 210 nm. The linearity for concentrations between 12.5μg/ml–75μg/ml for Metformin and 1.25μg/ml – 7.5μg/ml for Vildagliptin were established.  The limits of detection (LOD) and quantification were 1.75 and 5.29 µg/ml for metformin and 0.46 and 1.39 µg/ml for vildagliptin. The determination of the two active ingredients was not interfered by the excipients of the products. This method was satisfactorily applied to the analysis of the tablet formulations and proved to be specific and accurate for the quality control of the cited drugs in tablet dosage form.

The objective of this work was to develop and validate simple, rapid and accurate chromatographic method for determination of Desvenlafaxine succinate in solid dosage form. This RP-HPLC method was based on Reversed Phase High Performance Liquid Chromatography, on ODS C18 RP column (250 mm × 4.6 mm i.d., 5 μ), using Acetonitrile: Ammonium Phosphate buffer (pH 3.0) (70:30 v/v) as the mobile phase, at a flow rate of 1 mL/min at ambient temperature. Quantification was achieved by UV detection at 220 nm over a concentration range of 20-160 μg/mL for Desvenlafaxine succinate. The mean retention time for Desvenlafaxine succinate was found to be 2.44 min. The amount of Desvenlafaxine succinate estimated as percentage label claim was found to be 99.67. Key words: RP-HPLC, Desvenlafaxine succinate, marketed formulation.

An accurate & precise liquid chromatographic method was developed for the simultaneous estimation of Itopride (ITP) and Gliclazide (GCZ) in API matrix. The chromatographic analysis was performed on GRACE C18 [250 x 4.6 mm i.d, 5 µ particle size) with mobile phase consisting of 0.05M Potassium Dihydrogen phosphate and 0.5% Tri Ethyl Amine (TEA) buffer having pH 2.7 and Methanol in the ratio of 60:40 v/v at a flow rate of 0.8 mL/ min and UV detection was carried out at 238 nm. The calibration curves of peak area versus concentration, which was linear from 10 - 100 µg/mL for ITP and 5 – 50 µg/mL for GCZ respectively. The retention times of ITP and GCZ were 2.951 and 7.735 min respectively. The method had the requisite accuracy, precision and robustness for simultaneous determination of ITP & GCZ in API matrix. The percentage assays of ITP & GCZ were found out to be 100.80% and 99.76% respectively. The method was validated by determining its accuracy, precision and system suitability. The results of the study showed that the proposed RP-HPLC method is simple, rapid, precise and accurate, which is useful for the routine determination of ITP & GCZ in bulk drug and in its pharmaceutical dosage forms.

A simple, rapid reverse phase high performance liquid chromatographic method (RP- HPLC) has been developed and validated for simultaneous estimation of Aceclofenac and Pregabalin in tablet dosage form. Chromatographic separation was achieved C-18 (250 mm × 4.6 mm, 5.0μ) as stationary phase and mobile phase containing phosphate (pH adjusted to 5.0 ± 0.05 using NaOH.) Buffer: Acetonitrile (30:70 v/v) at flow rate of 1 ml/min using UV detection at 210 nm. The retention time for Aceclofenac and Pregabalin was found to be 3.177 and 5.530 min respectively. The method was validated as per International Conference on Harmonization guideline and successfully used for the quantitative analysis of commercially available tablet. The calibration curve was linear over the concentration range of 20-60μg/ml for Aceclofenac and 15-45μg/ml for Pregabalin.. Lower values of Limit of Detection (0.60μg/ml for Aceclofenac and 0.88μg/ml for Pregabalin) and Limit of Quantification (1.84μg/ml for Aceclofenac and 2.68μg/ml for Pregabalin ) indicated good sensitivity of the method. The method was validate with respect to linearity, robustness, precision and accuracy and was successfully applied for the simultaneous determination of aceclofenac and pregabalin from the combined dosage formulation. The percent amount for both the drugs were found to be within limits in the tablet dosage form for both the methods.

Two simple, sensitive and precise HPTLC and RP-HPLC methods were developed for the estimation of berberine from Coscinium fenestratum, and its formulation. For the determination of berberine by HPTLC method, precoated silicagel 60F254 on aluminium sheets and a mobile phase system comprising of n-butanol: glacial acetic acid : water (8:1:1 % v/v/v ) was selected. After development the plate was scanned and quantified at 350 nm. Linearity was found in the concentration range of 10 to 50 ng/spot (r=0.9992). Limit of detection was found to be 5 ng/spot and limit of quantification was found to be 10 ng/spot. In RP-HPLC method, separation was achieved on a Phenomenex, Luna, C18 column (150 x 4.6mm internal diameter, 5µ particle size) using a mobile phase consisting of potassium dihydrogen phosphate (pH - 2.5) (A)  : acetonitrile (B), where B was run in gradient programme (20% for 0.01-20min, 50% for 20-25min, 50% for 25-26min, 20% for 26-30min), at a flow rate of 1ml/min and the elute was monitored at 220nm. The calibration curve was obtained in the range of 100 - 500 µg/mL. The slope, intercept and correlation coefficient values were found to be 57588, 6041and 0.9959, respectively. The method was validated in compliance with ICH guidelines. Low relative standard deviation and good % recovery values of both the methods showed that the developed methods were highly precise, accurate and can be employed for the routine analysis of formulations containing berberine.

This research manuscript describes simple, sensitive, accurate, precise and repeatable reverse phase high performance liquid chromatography method for the estimation of Ketoconazole in tablet dosage form. The sample was analyzed by reverse phase ACE 5 C18 column (150 mm × 4.6 mm i.d, 5 μm particle size) as stationary phase; methanol: acidic water  [91:9, v/v] pH 3.0 as a mobile phase at a flow rate of 0.85 ml/min. Quantification was achieved with Photo Diode Array detector at 243 nm. The retention time for Ketoconazole was found to be 2.764 min. The linearity was obtained in the concentration range of 5-40 µg/ml for Ketoconazole. The method was successfully applied to tablet because no chromatographic interferences from formulation excipients were found. The method retained its accuracy and precision when the standard addition technique was applied.