scholarly journals Determination of Nebivolol Hydrochloride and Hydrochlorothiazide in Tablets by First-Order Derivative Spectrophotometry and Liquid Chromatography

2008 ◽  
Vol 91 (5) ◽  
pp. 1075-1082 ◽  
Author(s):  
Dimal A Shah ◽  
Kashyap K Bhatt ◽  
Rajendra S Mehta ◽  
Sunil L Baldania
Keyword(s):  
Liquid Chromatography ◽  
Internal Standard ◽  
Reversed Phase ◽  
Dosage Forms ◽  
Derivative Spectrophotometry ◽  
Order Derivative ◽  
First Order ◽  
Calibration Curves ◽  
Phase Liquid ◽  
Nebivolol Hydrochloride

Abstract Two simple and accurate methods for analysis of nebivolol hydrochloride (NEB) and hydrochlorothiazide (HCTZ) in their combined dosage forms were developed using first-order derivative spectrophotometry and reversed-phase liquid chromatography (LC). NEB and HCTZ in their combined dosage forms (tablets) were quantified using first-derivative responses at 294.6 and 334.6 nm in the spectra of their solutions in methanol. The calibration curves were linear in the concentration range of 840 g/mL for NEB and 1060 g/mL for HCTZ. LC analysis was performed on a Phenomenex Gemini C18 column (250 4.6 mm id, 5 m particle size) in the isocratic mode with 0.05 M potassium dihydrogen phosphateacetonitrilemethanol (30 + 20 + 50, v/v/v; pH 4) mobile phase at a flow rate of 1 mL/min. Detection was made at 220 nm. Both of the drugs and the internal standard (ezetimibe) were well resolved with retention times of 5.1 min for NEB, 2.9 min for HCTZ, and 8.2 min for ezetimibe. The calibration curves were linear in the concentration range of 114 g/mL for NEB and 0.328 g/mL for HCTZ. Both methods were validated and found to be accurate, precise, and specific, and results were compared statistically. Developed methods were successfully applied for the estimation of NEB and HCTZ in their combined dosage forms.

scholarly journals Estimation of Atorvastatin Calcium and Fenofibrate in Tablets by Derivative Spectrophotometry and Liquid Chromatography

2007 ◽  
Vol 90 (3) ◽  
pp. 700-705 ◽  
Author(s):  
Naresh V Nakarani ◽  
Kashyap K Bhatt ◽  
Rutva D Patel ◽  
Hemaxi S Bhatt
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Derivative Spectrophotometry ◽  
Second Derivative ◽  
Atorvastatin Calcium ◽  
Calibration Curves ◽  
Phase Liquid ◽  
Tablet Formulations ◽  
Method Analysis ◽  
Isocratic Mode

Abstract Two simple and accurate methods to determine atorvastatin calcium (ATO) and fenofibrate (FEN) in combined dosage forms were developed using second-derivative spectrophotometry and reversed-phase liquid chromatography (LC). ATO and FEN in combined preparations (tablets) were quantitated using the second-derivative responses at 245.64 nm for ATO and 289.56 nm for FEN in spectra of their solution in methanol. The calibration curves were linear [correlation coefficient (r) = 0.9992 for ATO and 0.9995 for FEN] in the concentration range of 315 g/mL for ATO and FEN. In the LC method, analysis was performed on a Hypersil ODS-C18 column (250 mm 4.6 mm id, 5 m particle size) in the isocratic mode using the mobile phase methanol-water (90 + 10, v/v), adjusted to pH 5.5 with orthophosphoric acid, at a flow rate of 1 mL/min. Measurement was made at a wavelength of 246.72 nm. Both drugs were well resolved on the stationary phase, and the retention times were 1.95 min for ATO and 5.50 min for FEN. The calibration curves were linear (r = 0.9985 for ATO and 0.9976 for FEN) in the concentration range of 315 g/mL for ATO and FEN. Both methods were validated, and the results were compared statistically. They were found to be accurate, precise, and specific. The methods were successfully applied to the estimation of ATO and FEN in combined tablet formulations.

scholarly journals High-performance liquid chromatography and derivative spectrophotometry for simultaneous determination of pravastatin and fenofibrate in the dosage form

2014 ◽  
Vol 64 (4) ◽  
pp. 433-446 ◽  
Author(s):  
Mohamed M. Hefnawy ◽  
Mostafa S. Mohamed ◽  
Mohammed A. Abounassif ◽  
Amer M. Alanazi ◽  
Gamal A. E. Mostafa
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
High Performance ◽  
Particle Diameter ◽  
Second Order ◽  
Derivative Spectrophotometry ◽  
Order Derivative ◽  
Calibration Curves

Abstract High performance liquid chromatography (HPLC) and second-order derivative spectrophotometry have been used for simultaneous determination of pravastatin (PS) and fenofibrate (FF) in pharmaceutical formulations. HPLC separation was performed on a phenyl HYPERSIL C18 column (125 mm × 4.6 mm i.d., 5 μm particle diameter) in the isocratic mode using a mobile phase acetonitrile/0.1 % diethyl amine (50:50, V/V, pH 4.5) pumped at a flow rate of 1.0 mL min-1. Measurement was made at 240 nm. Both drugs were well resolved on the stationary phase, with retention times of 2.15 and 5.79 min for PS and FF, respectively. Calibration curves were linear (R = 0.999 for PS and 0.996 for FF) in the concentration range of 5-50 and 20-200 µg mL-1 for PS and FF, respectively. Pravastatin and fenofibrate were quantitated in combined preparations also using the second-order derivative response at 237.6 and 295.1 nm for PS and FF, respectively. Calibration curves were linear, with the correlation coefficient R = 0.999 for pravastatin and fenofibrate, in the concentration range of 5-20 and 3-20 µg mL-1 for PS and FF, respectively. Both methods were fully validated and compared, the results confirmed that they were highly suitable for their intended purpose.

Measurement of gliclazide in plasma by radial compression reversed-phase liquid chromatography.

1984 ◽  
Vol 30 (11) ◽  
pp. 1789-1791 ◽  
Author(s):  
B G Charles ◽  
P J Ravenscroft
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Reversed Phase ◽  
Radial Compression ◽  
Reversed Phase Liquid Chromatography ◽  
Minimal Sample ◽  
Precise Analysis ◽  
Phase Liquid

Abstract We describe a rapid, specific, and precise analysis for gliclazide in plasma by radial compression, reversed-phase, "high-performance" liquid chromatography. Gliclazide and the internal standard, 3-chlorogliclazide, are eluted after 4.4 and 6.8 min, respectively. Only 100 microL of plasma and minimal sample workup are required. The limit of detection for gliclazide in plasma is 0.5 mg/L (1.55 mumol/L) at 229 nm. Precision (CV) of the assay for 10 and 1 mg of gliclazide per litre is 2.1% and 6.4%, respectively.

scholarly journals Estimation of Pioglitazone Hydrochloride and Metformin Hydrochloride in Tablets by Derivative Spectrophotometry and Liquid Chromatographic Methods

2005 ◽  
Vol 88 (4) ◽  
pp. 1167-1172 ◽  
Author(s):  
Madhira B Shankar ◽  
Vaibhav D Modi ◽  
Dimal A Shah ◽  
Kashyap K Bhatt ◽  
Rajendra S Mehta ◽  
...  
Keyword(s):  
Reversed Phase ◽  
Derivative Spectrophotometry ◽  
Metformin Hydrochloride ◽  
Second Derivative ◽  
Reversed Phase Liquid Chromatography ◽  
Calibration Curves ◽  
Phase Liquid ◽  
Tablet Formulations ◽  
Liquid Chromatographic ◽  
Method Analysis

Abstract Two simple and accurate methods of analysis to determine pioglitazone hydrochloride (PIO) and metformin hydrochloride (MET) in combined dosage forms were developed using second-derivative spectrophotometry and reversed-phase liquid chromatography (LC). PIO and MET in combined preparations (tablets) were quantified using the second-derivative responses at 227.55 nm for PIO and 257.25 nm for MET in spectra of their solutions in a mixture of methanol and acetonitrile (30 + 70). The calibration curves were linear [correlation coefficient (r) = 0.9984 for PIO and 0.9986 for MET] in the concentration range of 8–40 μg/mL for PIO and 4–12 μg/mL for MET. In the LC method, analysis was performed on a Hypersil ODS-C18 column with 5 μm particle size using the mobile phase acetonitrile-water-acetic acid (75 + 25 + 0.3), adjusted to pH 5.5 with liquor ammonia, at a flow rate of 0.5 mL/min. Measurement was made at a wavelength of 230 nm. Both the drugs were well resolved on the stationary phase, and the retention times were 8.5 min for PIO and 16.0 min for MET. The calibration curves were linear (r = 0.9933 for PIO and 0.9958 for MET) in the concentration range of 4–20 μg/mL for PIO and MET. Both methods were validated, and the results were compared statistically. They were found to be accurate, precise, and specific. The methods were successfully applied to the estimation of PIO and MET in combined tablet formulations.

scholarly journals Determination of Methomyl in Insecticidal Formulations by Reversed-Phase Liquid Chromatography: Collaborative Study

1996 ◽  
Vol 79 (4) ◽  
pp. 941-948
Author(s):  
James E Conaway ◽  
J B Audino ◽  
E Bane ◽  
S K Carrigan ◽  
R Glinsky ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Coefficient Of Variation ◽  
Mobile Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A reversed-phase liquid chromatographic (LC) method for methomyl was studied. Twelve collaborators analyzed 3 solid and 4 liquid formulations on both a Zorbax octadecylsilane (ODS) column and a similar column of their choice. Methomyl and the internal standard were separated by using a mobile phase consisting of approximately 8% acetonitrile in water, which was monitored at 254 nm. The coefficient of variation on the Zorbax column ranged from 0.70 to 5.23%, while the range on the collaborators' house columns was 1.08 to 6.01%. Results with the Zorbax ODS column fell within the 5% 2-tail limits, and 10 of 11 collaborators' results fell within these limits on house columns. The LC method for determination of methomyl in insecticidal formulations has been adopted first action by AOAC INTERNATIONAL.

Analysis of 5-Vinyl-l,3-Oxazolidine-2-Thione by Liquid Chromatography

1992 ◽  
Vol 75 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Alain Quinsac ◽  
Daniel Ribaillier ◽  
Patrick Rollin ◽  
Michel Dreux
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase ◽  
Internal Standard ◽  
Rapeseed Meal ◽  
Reversed Phase ◽  
Mercury Acetate ◽  
Phase Liquid ◽  
Biological Environment ◽  
Liquid Chromatographic

Abstract 5-Vlnyl-1,3-oxazolldlne-2-thlone (5-VOT) Is a goltrlgenlc compound released by enzymatic degradation of progoltrln, the major glucoslnolate occurring In rapeseed meal. A liquid chromatographic (LC) method for determination of 5-VOT in a biological environment Is presented. Complete extraction of 5-VOT has been carried out by complexatlon with phenyl mercury acetate under cyclohexanlc conditions, and then by decomplexation using an aqueous sodium thlosulfate solution. These reactions displace 5-VOT from an aqueous to an organic medium, and then back again to the aqueous condition, thus assuring high selectivity of the extraction. Precise quantitation of 5-VOT Is completed in 10 mln by reversed-phase liquid chromatography using an isocratic elutlon with UV detection and a specially made synthetic Internal standard. Concentration steps by solid-phase chromatography and evaporation can be introduced In the analytic procedure to lower the detection limit of 5-VOT in the sample used from 100 to 0.5 ppb. Using sow milk samples, the method was tested by small measured additions of 5-VOT. The recovery rate of the product was very good (>97%). Different phases used to achieve a sensitive, rapid, and precise method are described.

Nonaqueous reversed-phase liquid chromatography and fluorimetry compared for determination of retinol in serum.

1983 ◽  
Vol 29 (7) ◽  
pp. 1431-1434 ◽  
Author(s):  
H J Nelis ◽  
J De Roose ◽  
H Vandenbavière ◽  
A P De Leenheer
Keyword(s):  
Liquid Chromatography ◽  
Detection Limit ◽  
Internal Standard ◽  
Reference Method ◽  
Reversed Phase ◽  
Routine Method ◽  
Reversed Phase Liquid Chromatography ◽  
Standard Curve ◽  
Phase Liquid

Abstract A new assay for retinol in human serum, based on nonaqueous reversed-phase liquid chromatography, is presented. Sample preparation includes addition of the internal standard, retinyl propionate, deproteinization of 100 microL of serum with acetonitrile, and extraction with hexane. The standard curve is linear up to 2 mg/L. The assay is characterized by excellent sensitivity (detection limit, 15 micrograms/L) and good within-run and between-run precision (CVs of 2.6 and 2.7%, respectively), and results compare favorably with those by fluorimetry. We assayed 135 samples from hospitalized patients by both methods. Although the two sets of values correlated well (r = 0.955) the fluorimetric method occasionally suffers from interferences. In practice, fluorimetry proves valuable as a routine method, while liquid chromatography meets the criteria of a potential reference method.

Rapid assay for amino acids in serum or urine by pre-column derivatization and reversed-phase liquid chromatography.

1982 ◽  
Vol 28 (3) ◽  
pp. 527-531 ◽  
Author(s):  
D C Turnell ◽  
J D Cooper
Keyword(s):  
Amino Acids ◽  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Reversed Phase ◽  
Homocysteic Acid ◽  
Coefficients Of Variation ◽  
Peak Areas ◽  
Phase Liquid ◽  
The Mean

Abstract This method for estimating clinically important amino acids in serum or urine within 40 min involves o-phthalaldehyde/2-mercaptoethanol derivatization and reversed-phase "high-pressure" liquid chromatography. Homocysteic acid is an internal standard, and homoserine and norvaline are reference peaks. For all the amino acids estimated, the between-run coefficients of variation ranged from 2.0 to 13.5%, and the mean analytical recoveries from both serum and urine samples was 101%. Peak areas vary linearly with concentration up to 1500 mumol/L for all the amino acids assayed. The limit of detection for each amino acid was estimated to be 38 fmol.

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