A Stability-Indicating Hplc Analysis of Famotidine and Its Application to Kinetic Studies

Abstract

A stability-indicating HPLC analytical method has been developed for the determination of the H₂-receptor antagonist, famotidine in the presence of its degradation products. the method utilizes reversed phase chromatography with UV detection and internal calibration techniques. the mobile phase was comprised of 84% ammonium acetate buffer (pH 2.9) and 16% acetonitrile and pumped at a flow rate of 1.5 ml/min. Quantitation was performed by measuring the peak height ratio of drug to internal standard (salicylic acid). the limit of famotidine detection was determined to be 10 ng (0.4 ug/ml) with a signal to noise ratio of 3:1. Within day coefficient of variation of the method was 2.22% (2.5 μg/ml) and 0.82% (10 μg/ml). Between day coefficient of variation based on the slopes of daily prepared standard curves was 4.70%. the developed method was used to determine the drug content of famotidine tablets. Further, it was used to investigate the kinetics of degradation of the drug in an acidic solution.     

Kinetic Spectrophotometric Determination of Ranitidine

Two spectrophotometric methods were developed for the determination of ranitidine. The first method was a kinetic spectrophotometric method based on the catalytic effect of ranitidine on the reaction between sodium azide and iodine in an aqueous solution. The calibration graph was linear from 4–24 μg/mL. The drug was determined by measuring the decrease in the absorbance of iodine at 348 nm using a fixed time method. The decrease in the absorbance after 1 minute from the initiation of the reaction was related to the concentration of drug. The detection limit of the procedure was 0.76 μg/mL. The proposed procedure was successfully utilized in the determination of the drug in pharmaceutical preparations with mean recovery in the range of 99.83 ? 101.16%. The second method is a colorimetric method, which depends on the measurement of absorbances of tris (o‐phenanthroline) iron(II) [method 2A] and tris (bipyridyl) iron(II) [method 2B] complexes at 512 nm. The complexes obeyed Beer's law over the concentration range of 2–16 μg/mL and 4–40 μg/mL for methods 2A and 2B, respectively. The developed method has been successfully applied for the determination of ranitidine in bulk drugs and pharmaceutical formulations. The common excipients and additives did not interfere in its determination.     

Spectrophotometric Determination of Metoclopramide in Pharmaceutical Preparations

A simple and rapid spectrophotometric method for the determination of metoclopramide is described. The method is based upon simple diazotization reactions with nitrite and aniline as the coupling reagent. The absorbance was measured at 410 nm. The method was optimized for acidity, the amount of reagents required, and the amount of sodium hydroxide. The range of linearity was 0.5–12.0 µg/mL. The method was successfully applied to the determination of metoclopramide in pharmaceutical preparations without any interference from common excipients.__________From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 7, 2005, pp. 711–714.Original English Text Copyright © 2005 by Shah, Rasul Jan, Azam Khan, Amin.The text was submitted by the authors in English.     

Spectrophotometric and Spectrofluorimetric Determination of Famotidine and Ranitidine Using 1,4-Benzoquinone Reagent

ABSTRACT

Spectrophotometric and spectrofluorimetric methods were adopted for the analysis of Famotidine and Ranitidine depending on their reaction with 1,4 Benzoquinone reagent at pH 5.2 and 5.6, respectively. The absorbances of the resulting condensation products were measured at 502 and 508 nm for Famotidine and Ranitidine, respectively. Concentrations adhering to Beer's law were from 40-160 μg.ml^? for Famotidine and from 20-100 μg.ml^? for Ranitidine.

Furthermore the resulting condensation products exhibited fluorescence at 665 nm when excited at 290 nm and the calibration graphs were rectilinear from 0.4-1.4 μg.ml^? for Famotidine and from 0.21 μg.ml^? for Ranitidine.

Different parameters affecting these reactions were thoroughly studied. Also these methods were applied to the pharmaceutical preparations and the results were satisfactory. The validities of the methods were ascertained by the standard addition technique revealing fine results in consideration to the mean recovery percent and standard deviation.

The spectrofluorimetric method was a hundred times more sensitive then the spectrophotometric method. The proposed methods were sensitive, accurate, and precise as statistically compared with the official methods of analysis of Famotidine and Ranitidine.     

Kinetic and Spectrophotometric Determination of Thioctic Acid in Bulk and Pharmaceutical Formulations

Three simple and sensitive spectrophotometric methods were developed for the determination of thioctic acid in bulk and in its pharmaceutical preparations using iron(III) as an oxidizing agent. Method A is based on kinetic investigation of oxidation reaction of the drug with iron(III) and a subsequent chelation of the produced iron(II) with ferricyanide to form prussian blue colored product at room temperature for a fixed time of 15 minutes at 750 nm. Methods B and C are based on oxidation of the studied drug with iron(III). The equivalent iron(II) produced is allowed to react with either o‐phenanthroline or bipyridyl to give colored species measurable at 510, 522 nm, respectively. Regression analysis of Beer‐Lambert plots showed a good correlation in the concentration ranges of 0.4–4 μg/mL with a detection limit of 0.095 μg/mL for method A and 0.5–5 μg/mL with detection limits 0.137 and 0.127 for method B and C, respectively. The three methods were successfully applied for the determination of the drug in its dosage forms. The percentage recoveries were 99.88 ± 1.40, 99.98 ± 1.26 and 100.64 ± 1.07, respectively.     

动力学光度法测定痕量镉的研究

本研究了氨水介质中，痕量镉阻抑过氧化氢氧化偶氮胂１褪色的新指示反应及其动力学条件，建立了动力学光度法测定痕量镉的新方法，方法检出限为２．７×１０＾－１２ｇＣｄ＾２＋／ｍｌ，测定范围为０－１．０μｇＣｄ＾２＋／２５ｍｌ。     

Kinetic Spectrophotometric Determination of Acetaldehyde

ABSTRACT

A method for determination of trace quantities of acetaldehyde based on its inhibition effect on the malachite green-sulfite reaction is described. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance at 613 nm by a fixed time method of 60 seconds. The method allows the determination of acetaldehyde in the range of 0.2-10 μg/ml. The limit of detection was 0.1 μg/ml and the relative standard deviation for ten determinations of 2 μg/ml acetaldehyde was 1.8%. The method is applied to the determination of acetaldehyde in chemical industrial waste water with satisfactory results.     

Flow Injection Analysis of Famotidine with Spectrophotometric Detection

Abstract

A flow injection determination of famotidine has been described. The method is based on the reaction of the drug with cupric acetate to form a blue coloured complex which shows absorption maxima at 314 nm and 630 nm. For an injection volume of 100 μl calibration graphs were rectilinear from 10- 50 μg. ml^?1 and 50–500 μg.ml^?1 of drug at the two wavelengths respectively. Samples could be analysed at rates upto 60 per hour with a relative standard deviation less than 1.4%. The method was evaluated by analysis of the pure drug and commercial formulations. The results compare well with those obtained by official methods.     

Simultaneous Spectrophotometric Determination of Hydrochlorothiazide and Pharmaceutical Preparations

Abstract

We developed three methods for the simultaneous determination of amiloride (AMI) and hydrochlorothiazide (HCT): zero-crossing, derivative quotient spectra with normalized divisor and multiple linear regression (MULTIC) methods. The two first methods use the derivative spectrophotometry, and the last one uses the absorbance measurement. The three methods were used to determine both compounds in synthetic mixtures and pharmaceutical preparations with errors less than 5% and 15%, respectively.     

Spectrophotometric Determination of Methyldopa in Pure and Pharmaceutical Preparations

Abstract

Methyldopa reacts with barbituric acid to give a red colour having maximum absorbance at 540 nm. The reaction is selective for methyldopa with 0.01 mg/ml as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer's Law from 0.1 mg to 2.5 mg/10 ml of methyldopa and the relative standard deviation is 1.1%. The quantitative assessment of tolerable amount of other drugs is also studied.     

Spectrophotometric Determination of Certain Local Anaesthetics in Pharmaceutical Preparations

Abstract

A direct colorimetric method was described for the rapid, sensitive and accurate determination of dibucaine, lidocaine, bupivacaine, procaine and tetracaine in pharmaceutical preparations. The method involves the use of haematoxylin reagent in the presence of boric acid to give a reddish-violet chromogen (λ_max = 555 nm). Beer's law was obeyed in the range from 2–60 μg/ml. No interference was observed from the commonly present additives or agents in pharmaceutical formulations.     

Spectrophotometric Determination of Naproxen in Pure and Pharmaceutical Preparations

ABSTRACT

Naproxen reacts with 1-naphthylamine and sodium nitrite to give an orangish red colour having maximum absorbance at 460-480 nm (working wavelength 480 nm). The reaction is selective for naproxen with 0.001 mg/ml as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The reaction obeys Beer's law from 0.01mg to 6.5 mg/10ml of naproxen and the relative standard deviation is 1.5%. The quantitative assessment of tolerable amount of other drugs is also studied.     

阻抑动力学光度法测定痕量间二硝基苯的研究

研究发现 ,在硫酸介质中 ,痕量间二硝基苯能灵敏地阻抑 Fe3+催化高碘酸钾氧化甲基兰褪色。研究了该阻抑褪色反应的最佳条件及动力学参数 ,建立了一种测定痕量间二硝基苯的新方法。该法测定线性范围为 0 .0～ 8.0μg/L,检出限为 1 .6× 1 0 - 6 g/L。用于环境水样中间二硝基苯的测定 ,结果满意     

动力学分光光度法快速测定高pH值

传统的pH值玻璃电极传感器在pH 1·0~12·0的范围内具有很好的准确性,但在pH<1·0和pH>12·0的条件下会产生“酸误”和“碱误”[1-3]。氢氧化钠是最常用的化学试剂之一,因此它的准确测定在各种工业过程如产品的质量控制,环境污染控制,以及设备腐蚀控制过程中等具有重要作用。已     

动力学分光光度法测定痕量亚硝酸根和硫氰酸根的研究

基于亚硝酸根对溴酸钾氧乙基橙反应的催化作用及硫氰酸根对此反应的抑制作用，建立了动力学光度法测定痕量亚硝酸根和硫氰酸根的新方法，测定亚硝酸根的线性范围为５－１００μｇ／Ｌ，测定硫氰酸根的线性范围为３－１２μｇ／Ｌ，用于湖水和蔬菜中的亚硝酸根量及化学试剂和尿中的硫氰酸根测定，结果满意。     

Kinetic Spectrophotometric Determination of Ritodrine Hydrochloride in Dosage Forms

A simple and sensitive kinetic method was developed for the determination of ritodrine hydrochloride in pharmaceutical preparations. The method is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permenganate at room temperature for a fixed 12.5 min; the absorbance of the colored permenganate ion was measured at 609 nm. The absorbance concentration plots were rectilinear over the range of 1.6–11.2 μg mL^?1 (r = 0.9992) with a minimum detectability of 0.096 μgmL^?1 (2.88 × 10^?7 M). The different experimental parameters affecting the development and stability of color were carefully studied and optimized. The determination of ritodrine hydrochloride by the fixed concentration and rate constant methods is also feasible with the calibration equations obtained, but the fixed time method has been found to be more applicable. The proposed method was applied successfully to the determination of ritodrine hydrochloride in tablets and ampoules with average recoveries of 100.37 ± 0.93% and 100.42 ± 0.87%, respectively. The results obtained were in good agreement with those obtained using a reference method for comparison. A proposal of the reaction pathway is also presented.     

Spectrophotometric Determination of Phenytoin Sodium in Pure and Pharmaceutical Preparations

 Phenytoin sodium reacts with o-nitrobenzoic acid in alkaline media after heating for 10 minutes at 70 °C, to give a red coloured complex having maximum absorbance at 510 nm. The reaction is selective for phenytoin sodium with 0.01 mg/10 mL as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from 0.01 mg to 3 mg/10 mL of phenytoin sodium and the relative standard deviation is 0.29%. The quantitative assessment of tolerable amounts of other drugs is also studied. Received May 2, 2000. Revision May 11, 2001.     

Spectrophotometric Determination of Prochlorperazine Maleate in Pure and Pharmaceutical Preparations

 Prochlorperazine maleate reacts with 1-naphthylamine and sodium nitrite, after heating for 110 s at 80 °C to give an orange red colour having maximum absorbance at 460 nm. The reaction is selective for prochlorperazine maleate with 0.01 mg/mL as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from 0.01 mg/10 mL to 0.33 mg/10 mL of prochlorperazine maleate and the relative standard deviation is 0.68%. The quantitative assessment of tolerable amounts of other drugs is also studied. Received September 22, 2000. Revision June 19, 2001     

动力学分光光度法测定痕量硫氰酸根的研究

利用SCN~-对溴酸钾氧化罗丹明B反应的抑制作用。建立了动力学光度法测定痕量SCN~-的新方法。检出限为0.30ng SCN~-/ml,测定范围为0.30～8.3ngSCN~-/ml.应用于吸烟者与不吸烟者尿中SCN~-的测定。结果较为满意。