Search Results

You are looking at 21 - 30 of 186 items for :

  • All content x
Clear All

chromatography (RP-HPLC) has been developed for trace level quantification of methyl vinyl ketone [ 13 ]. However, according to the available literature, there are still no papers dealing with comprehensive purity assessment of ivabradine as active pharmaceutical

Open access

best glucose control in blood and for better compliance to therapy [ 6 ]. To the best of our knowledge, it is revealed that several reversed-phase high-performance liquid chromatography (RP-HPLC) methods are available for the determination of MTF and

Open access

, respectively. This method showed a sufficient linearity (≥0.999) according to Center for Drug Evaluation and Research [ 18 ], which is a better correlation coefficient than that with an reversed-phase HPLC (RP-HPLC) method published previously by Jeyaprakash et

Open access

Summary

A sensitive and reproducible HPLC method has been developed for quantitative analysis of telmisartan. The drug was separated from its degradation products on a C18 column at ambient temperature with methanol-water 80:20 (v/v), pH 4.0 (adjusted by addition of orthophosphoric acid), as mobile phase at a flow rate of 1.0 mL min−1. Under these conditions the retention time of telmisartan was 4.85 ± 0.05 min. Quantification on the basis of peak area was achieved by UV detection at 225 nm; calibration plots were linear in the concentration range 10–60 μg mL−1. When the method was applied to a pharmaceutical formulation there was no chromatographic interference from tablet excipients. The method was validated for precision, robustness, recovery, and limits of detection and quantification. The drug was subjected to acidic and alkaline hydrolysis, and oxidising, dry heat, wet heat, and photodegrading conditions. Because the method could effectively separate the drug from its degradation products, it can be regarded as stability indicating.

Full access

robustness was examined by testing the samples under a minor variety of experimental conditions. For RP-HPLC methods, small changes in the pH (±0.2), small changes in percentage of acetonitrile by up to ±2% were introduced to the mobile phase, small changes

Open access

Summary

A sensitive validated high-performance liquid-chromatographic method for analysis of cilostazol in human plasma (in vitro) has been developed, and it was applied to determine pharmacokinetics of cilostazol in male albino rabbit. Cilostazol was extracted from human plasma (in vitro) by acetonitrile, and efficient chromatographic elution was achieved on a C18 column (250 × 4.60 mm i.d., 0.5 μm particle size) with an isocratic mobile phase [acetonitrile-50 mM acetate buffer (pH 5.0, glacial acetic acid)-water (50:20:30)] at flow rate of 1.5 mL min−1. Quantification was carried out by photo-diode array (PDA) detection at 248 nm. The linearity of the method was excellent over the range 0.2–2 μg mL−1 with low limits of detection (0.005 μg mL−1) and quantification (0.05 μg mL−1). The extraction recovery of the drug from plasma was consistently good (73.45–78.64%), with low relative standard deviation (0.44–1.65%). Robustness studies confirmed that peak area was unaffected by small changes in temperature, mobile phase (composition and pH). The maximum concentration (C max) in rabbit (in vivo) was determined 1.620 μg mL−1 at t max (0.51 h) with 0.63% RSD by validated bioanalytical method.

Full access

In order to assess the contribution of adenosine triphosphate and its metabolites to the cellular metabolism process in Saccharomyces cerevisiae, it is very important to simultaneously determine the relative concentrations of ATP and its metabolites. In this study, a fast, simple reversed-phase high-performance liquid chromatography with high selectivity was developed to simultaneously measure adenosine triphosphate and its metabolites (adenosine diphosphate, adenosine monophosphate, and cyclic adenosine monophosphate) in yeast. The method was performed under the gradient grogram, and the detection was monitored at 254 nm. Analysis was achieved within 25 min. The four components can be detected with linear response over the concentration range from 1 to 100 mg L−1 with excellent correlation coefficients (r 2) > 0.999. The recovery of the four analytes was 92.9%, 90.4%, 99.1%, and 105.1%, respectively. To demonstrate the good analysis of yeast samples, changes in the four adenine nucleotides levels caused by caloric restriction in yeast were determined. It is expected that the current method may contribute to further metabolomics and system biology investigations of yeast.

Open access

Summary

A simple, rapid reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous estimation of drotaverine and omeprazole in a tablet dosage form. A C18 column was used with a 60:40 (v/v) mixture of methanol and ammonium acetate (0.1 m, pH 5, adjusted with orthophosphoric acid) as mobile phase at a flow rate of 1.5 mL min−1. UV detection was performed at 319 nm. The method was validated for accuracy, precision, linearity, specificity and sensitivity in accordance with International Conference on Harmonisation guidelines. The method was successfully used for quantitative analysis of Ranipas-DV tablets. Total run time was 10 min, drotaverine and omeprazole were eluted with retention times of 7.969 and 6.538 min respectively. Validation revealed that the method is specific, accurate, precise, reliable and reproducible. Calibration plots were linear over the concentration ranges 5–40 μg mL−1 for drotaverine and 5–50 μg mL−1 for omeprazole, respectively. Limits of detection were 16.2 and 4.8 ng mL−1 and limits of quantification were 49.0 and 14.5 ng mL−1 for drotaverine and omeprazole, respectively. Recovery was in the range 100.66–100.94% and 102.42–102.89% for drotaverine and omeprazole, respectively, and the coefficient of variance was <2.0% for both. The high percentage recovery and low co-efficient of variation confirm the suitability of the method for simultaneous analysis of drotaverine and omeprazole in tablets.

Full access

Summary

A simple, precise, rapid, and accurate liquid chromatography-mass spectrometry (LC-MS) compatible reversed phase high-performance liquid chromatography-photodiode array detection (RP-HPLC-PDA) method has been developed and validated for the estimation of oxcarbazepine (OXC) in bulk and tablet formulations. The chromatographic separation was achieved on Phenomenex C18 column (150 mm · 4.6 mm, 5.0 μm particle size) using the mobile phase comprising methanol-formic acid (0.02% v/v in water) in the ratio of 50:50 (v/v) at a flow rate of 1 mL min−1, and OXC was eluted at 6.4 min. Quantification and linearity were achieved at 229 nm over the concentration range of 10–50 μg mL−1, and the mean percentage of assay was found to be 100.03. The method was validated for specificity, linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), stability, and robustness as per the International Conference on Harmonisation (ICH) guidelines and it is suitable to be employed in quality control.

Full access

Summary

Reversed phase high-performance liquid chromatography (RP-HPLC) and thin-layer chromatography (TLC)-spectrodensitometric methods have been developed and validated for the separation and quantitation of two binary mixtures: Ofloxacin (OFX) and dexamethasone (DXM) in eye preparation; ciprofloxacin hydrochloride (CIP) and hydrocortisone (HYD) in ear preparation. The linearity ranges of RP-HPLC methods were found to be (2.5–45 μg mL−1) for OFX, (2.5–50 μg mL−1) for DXM and (1–8 μg mL−1) for both CIP and HYD. The percentage recoveries/relative standard deviation (RSD) were found to be 100.36/1.38, 100.13/1.49, 99.98/0.61 and 100.28/1.27, respectively. The linearity ranges of TLC-spectrodensitometric methods were found to be (0.5–2 μg band−1), (0.5–3.5 μg band−1), (0.2–1.6 μg band−1), and (0.6–2 μg band−1) for OFX, DXM, CIP, and HYD, respectively. The percentage recoveries/RSD were found to be 99.98/1.06, 99.93/1.18, 99.74/1.27, and 99.94/1.54, respectively. A comparative study was conducted to show the advantages of the proposed methods which showed that the TLC-spectrodensitometric methods were simpler, more sensitive, and economic, while RP-HPLC methods were more precise and robust. The methods were validated in compliance with the ICH guidelines and were successfully applied for determination of the selected drugs in their laboratory-prepared mixtures and commercial dosage forms.

Full access