Application of Oxidizing Properties of Permanganate to the Determination of Famotidine in Pharmaceutical Formulations

One titrimetric and two spectrophotometric methods are described for the determination of famotidine (FMT) in either pure form or in its pharmaceutical formulations. The methods are based on redox reaction between FMT and KMnO(4) in acid and alkaline media. In titrimetry, an acidified solution of FMT is titrated directly with permanganate. Direct spectrophotometry (method A) involves treating the alkaline solution of the drug with permanganate and measuring the bluish green product at 610 nm. In indirect spectrophotometry (method B), the drug solution is treated with a fixed concentration of permanganate in H(2)SO(4) medium, and after a specified time, the unreacted permanganate is measured at 545 nm. The molar combining ratio in titrimetry and the optimum assay conditions are studied. Titrimetry is applicable over 1-10 mg range and the calculations are based on a 1:3 (FMT: KMnO(4)) molar-ratio. In spectrophotometry, Beer's law is obeyed over 0.75-7.5 and 2.5-20 mu g mL(-1) for method A and method B, respectively. The molar absorptivity values are calculated to be 2.79 x 10(4) and 1.62 x 10(4) L mol(-1) cm(-1) for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.012 and 0.021 mu g cm(-2). The limits of detection (LOD) and quantification (LOQ) are also reported for the spectrophotometric methods. The applicability of the developed methods was demonstrated by the determination of FMT in pure drug as well as in commercial dosage forms

SPECTROPHOTOMETRIC DETERMINATION OF ETAMSYLATE IN PHARMACEUTICALS USING FERRIC CHLORIDE BASED ON COMPLEX FORMATION REACTIONS

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Spectrophotometric determination of etamsylate in pharmaceuticals using ferric chloride based on complex formation reactions

The present study describes two simple and selective spectrophotometric methods for the rapid determination of etamsylate (ETM) in bulk and in capsule formulations. The methods are based on the oxidation of ETM with ferric chloride in neutral medium and subsequent chelation of the resulting iron(II) with 1,10-phenanthroline (Phen) (method A) and with 2,2’-bipyridyl (Bipy) (method B). The resulting red colored chromogens are measured at 510 and 520 nm, in method A and B, respectively. In both methods, the absorbance is found to increase linearly with increasing ETM concentration. Beer’s law is obeyed over the ranges 0.5-10 and 0.8-16 µg/ml for method A and B, respectively. The calculated molar absorptivity values are 2.17x104 and 1.65x104 l mol-1 cm-1 for method A and B, respectively, and the corresponding sandell sensitivities are 0.012 and 0.016 µg/cm2. Intra-day and inter-day precision and accuracy of the methods were established according to ICH guidelines. The proposed methods were applied to determine ETM in dosage forms and the results were statistically compared with that of an official BP metho

Development of a simple UV-spectrophotometric method for the determination of lansoprazole and study of its degradation profile

A UV-spectrophotometric method is described for the determination of lansoprazole (LAN). The method is based on the measurement of the absorbance of LAN solution in acetonitrile at 281 nm. The system obeyed Beer's law over the concentration range of 1.25-25.0 µg/mL. The degradation behavior of LAN was investigated under dry heat treatment, UV-degradation, acid hydrolysis, alkali hydrolysis and oxidation; and found to degrade extensively under acid hydrolysis, alkali hydrolysis and oxidation. The method was applied to the determination of LAN in capsule and the results were statistically compared with those of the reference method by applying Student's t-test and F-test

Development of a simple UV-spectrophotometric method for the determination of lansoprazole and study of its degradation profile

A UV-spectrophotometric method is described for the determination of lansoprazole (LAN). The method is based on the measurement of the absorbance of LAN solution in acetonitrile at 281 nm. The system obeyed Beer's law over the concentration range of 1.25-25.0 µg/mL. The degradation behavior of LAN was investigated under dry heat treatment, UV-degradation, acid hydrolysis, alkali hydrolysis and oxidation; and found to degrade extensively under acid hydrolysis, alkali hydrolysis and oxidation. The method was applied to the determination of LAN in capsule and the results were statistically compared with those of the reference method by applying Student's t-test and F-test

Rapid titrimetric and spectrophotometric determination of ofloxacin in pharmaceuticals using N-bromosuccinimide

One titrimetric and two spectrophotometric methods have been described for the determination of ofloxacin (OFX) in bulk drug and in tablets, employing N-Bromosuccinimide as an analytical reagent. The proposed methods involve the addition of a known excess of NBS to OFX in acid medium, followed by determination of unreacted NBS. In titrimetry, the unreacted NBS is determined iodometrically, and in spectrophotometry, unreacted NBS is determined by reacting with a fixed amount of either indigo carmine (Method A) or metanil yellow (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of OFX. Titrimetry allows the determination of 1-8 mg of OFX and the calculations are based on a 1:5 (OFX:NBS) reaction stoichiometry. In spectrophotometry, Beer's law is obeyed in the concentration ranges 0.5-5.0 µg/mL for method A and 0.3-3.0 µg/mL for method B. The molar absorptivities are calculated to be 5.53x10(4) and 9.24x10(4) L/mol/cm for method A and method B, respectively. The methods developed were applied to the assay of OFX in tablets, and results compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via the standard-addition method.<br>Descrevem-se métodos, um titulométrico e dois espectrofotométricos, para a determinação de ofloxacino (OFX) na matéria-prima e em comprimidos, empregando a N-bromossuccinimida (NBS) como reagente analítico. Os métodos propostos envolvem a adição de excesso conhecido de NBS ao OFX, em meio ácido, seguida de determinação do NBS que não reagiu. Na titulometria, o NBS que não reagiu é determinado iodometricamente e na espectrofotometria, o NBS que não reagiu é determinado pela reação com quantidade fixa de índigo carmim (Método A) ou amarelo de metanila (Método B). Em todos os métodos, a quantidade de NBS que reagiu corresponde à quantidade de OFX. A titulometria permite a determinação de 1-8 mg de OFX e os cálculos se baseiam na estequiometria de reação de 1:5 (OFX:NBS). Na espectrofotometria, a Lei de Beer é obedecida nas faixas de concentração de 0,5-5,0 µg/mL, para o método A, e de 0,3-3,0 µg/mL, para o método B, respectivamente. Os métodos desenvolvidos foram aplicados para o teste de OFX em comprimidos e os resultados foram comparados estatisticamente com aqueles do método de referência. A precisão e a confiabilidade dos métodos foram, posteriormente, verificadas por meio dos testes de recuperação via método de adição de padrão