Zero-Order and First-Derivative Spectrophotometry Deteraination of Trace Amounts of Ruthenium After Extraction of Its Ion Association Complex with 2,4,6-tris(2″-Pyridyl)-1,3,5-triazine and Picrate

Losartan potassium is an antihypertensive non-peptide agent, which exerts its action by specific blockade of angiotensin II receptors. The aim of the present study was the validation and application of analytical methods for the quality control of losartan potassium 50 mg in pharmaceutical capsules, using direct and first-derivative UV spectrophotometry. Based on losartan potassium spectrophotometric characteristics, a signal at 205 nm of the zero-order spectrum and a signal at 234 nm of the first-derivative spectrum, were found adequate for quantification. The results were used to compare these instrumental techniques. The linearity between the signals and concentrations of losartan potassium in the ranges of 3.0-7.0 mg L-1 and 6.0-14.0 mg L-1 for direct and first-derivative spectrophotometry in aqueous solutions, respectively, presented a correlation coefficient (r) of 0.9999 in both cases. The methods were applied for losartan potassium in capsule dosage obtained from local pharmacies, and were shown to be efficient, easy to apply and low cost. These methods do not use polluting reagents and require relatively inexpensive equipment.

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HIGH PERFORMANCE LIQUID CHROMATOGRAPHY, TLC-DENSITOMETRY, AND FIRST-DERIVATIVE SPECTROPHOTOMETRY FOR SIMULTANEOUS DETERMINATION OF AMLODIPINE AND PERINDOPRIL IN BULK POWDER AND ITS TABLETS

Journal of Liquid Chromatography &amp Related Technologies ◽

10.1080/10826076.2012.686141 ◽

2013 ◽

Vol 36 (10) ◽

pp. 1323-1339 ◽

Cited By ~ 2

Author(s):

Samia M. Gizawy ◽

Loris I. Bebawy ◽

Osama H. Abdelmageed ◽

Mahmoud A. Omar ◽

Sayed M. Deryea ◽

...

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Simultaneous Determination ◽

High Performance ◽

Derivative Spectrophotometry ◽

First Derivative ◽

Bulk Powder ◽

First Derivative Spectrophotometry

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Liquid Chromatographic and Spectrophotometric Determination of Diflucortolone Valerate and Isoconazole Nitrate in Creams

Journal of AOAC International ◽

10.1093/jaoac/94.1.128 ◽

2011 ◽

Vol 94 (1) ◽

pp. 128-135 ◽

Cited By ~ 1

Author(s):

Elif Karacan ◽

Mehmet Gokhan Çaġlayan ◽

İsmail Murat Palabiyik ◽

Feyyaz Onur

Keyword(s):

Principal Component Regression ◽

Principal Component ◽

Derivative Spectrophotometry ◽

Data Matrix ◽

Concentration Data ◽

Spectrophotometric Methods ◽

First Derivative ◽

First Derivative Spectrophotometry ◽

Liquid Chromatographic

Abstract A new RP-LC method and two new spectrophotometric methods, principal component regression (PCR) and first derivative spectrophotometry, are proposed for simultaneous determination of diflucortolone valerate (DIF) and isoconazole nitrate (ISO) in cream formulations. An isocratic system consisting of an ACE® C18 column and a mobile phase composed of methanol–water (95+5, v/v) was used for the optimal chromatographic separation. In PCR, the concentration data matrix was prepared by using synthetic mixtures containing these drugs in methanol–water (3+1, v/v). The absorbance data matrix corresponding to the concentration data matrix was obtained by measuring the absorbances at 29 wavelengths in the range of 242–298 nm for DIF and ISO in the zero-order spectra of their combinations. In first derivative spectrophotometry, dA/dλ values were measured at 247.8 nm for DIF and at 240.2 nm for ISO in first derivative spectra of the solution of DIF and ISO in methanol–water (3+1, v/v). The linear ranges were 4.00–48.0 μg/mL for DIF and 50.0–400 μg/mL for ISO in the LC method, and 2.40–40.0 μg/mL for DIF and 60.0–260 μg/mL for ISO in the PCR and first derivative spectrophotometric methods. These methods were validated by analyzing synthetic mixtures. These three methods were successfully applied to two pharmaceutical cream preparations.

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Spectrophotometric Stability-Indicating Methods for the Determination of Leflunomide in the Presence of Its Degradates

Journal of AOAC International ◽

10.1093/jaoac/89.6.1524 ◽

2006 ◽

Vol 89 (6) ◽

pp. 1524-1531 ◽

Cited By ~ 6

Author(s):

Samah S Abbas ◽

Lories I Bebawy ◽

Laila A Fattah ◽

Heba H Refaat

Keyword(s):

Dosage Forms ◽

Derivative Spectrophotometry ◽

Reaction Conditions ◽

Pharmaceutical Dosage Forms ◽

First Derivative ◽

Beer's Law ◽

First Derivative Spectrophotometry ◽

Colored Product ◽

Beer’S Law

Abstract Five simple and sensitive methods were developed for the determination of leflunomide (I) in the presence of its degradates 4-trifluoromethyl aniline (II) and 3-methyl-4-carboxy isoxazole (III). Method A was based on differential derivative spectrophotometry by measuring the △1D value at 279.5 nm. Beer's law was obeyed in the concentration range of 2.0020.00 μg/mL with mean percentage accuracy of 100.07 1.32. Method B depended on first-derivative spectrophotometry and measuring the amplitude at 253.4 nm. Beer's law was obeyed in the concentration range of 2.0016.00 μg/mL with mean percentage accuracy of 98.42 1.61. Method C was based on the reaction of degradate (II) with 2,6-dichloroquinone-4-chloroimide (Gibbs reagent). The colored product was measured at 469 nm. Method D depended on the reaction of degradate (II) with para-dimethyl aminocinnamaldehyde (p-DAC). The absorbance of the colored product was measured at 533.4 nm. Method E utilized 3-methyl-2-benzothiazolinone hydrazone in the presence of cerric ammonium sulfate with degradate (II). The green colored product was measured at 605.5 nm. The linearity range was 40.00-280.00, 2.40-24.00, and 30-250 μg/mL with mean percentage accuracy of 100.75 1.21, 100.13 1.45, and 99.74 1.39 for Methods CE, respectively. All variables were studied to optimize the reaction conditions. The proposed methods have been successfully applied to the analysis of leflunomide in pharmaceutical dosage forms and the results were statistically compared with that previously reported.

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