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

Abstract

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. 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.Unitermos: Ofloxacino/determinação. Titulometria/análise quantitativa. Espectrofotometria/análise quantitativa. N-Bromossuccinimida. Comprimidos/análise quantitativa.

Determination of Solifenacin Succinate in Pure and Pharmaceutical Dosage forms by Spectrophotometry

“…We have previously demonstrated the applicability of NBS for the determination of such drugs as dexmedetomidine hydrochloride [33], phenylephrine hydrochloride and pyridoxine hydrochloride [34]. NBS was also used in the determination of many compounds including pizotifen maleate [35], metaprolal tartrate [36], ofloxacin [37], pantoprazole sodium [38], gemifloxacin mesylate and moxifloxacin HCl [39] as well as fluoroquinolone [40].…”

Spectrophotometric determination of some analgesic drugs in pharmaceutical formulations using N-bromosuccinimide as an oxidant

“…NBS is widely used as an oxidizing or brominating reagent for the determination of many pharmaceutically important compounds (Zenita and Basavaiah, 2011;Vinay et al, 2011). It is also a specific reagent for the bromination of organic compounds at allylic position (Morison and Boyd, 1992).…”

Selective Potentiometric Sensors for the Determination of Quetiapine Fumarate in Pharmaceuticals and Spiked Human Urine

“…Many analytical methods are reported by different workers for the determination of QTF in pure form, formulations and in biological materials. High-performance liquid chromatography (HPLC) [4][5][6][7][8][9][10][11][12], ultra-performance liquid chromatographic with tandem mass spectrometry (UPLC-MS) [13,14], HPLC with different detection systems such as chemiluminescence [15], electrospray ionization mass spectrometry (ESI-MS) [16][17][18][19] and tandem mass spectrometry [20][21][22][23][24], and gas chromatography [25,26] techniques have been used for the assay of QTF in body fluids. However, QTF has been determined in pharmaceuticals by titrimetric [27,28], potentiometric [29], polarographic [30], differential pulse and square wave voltammetric [31], capillary zone electrophoretic [32,33], high performance thin layer chromatographic (HPTLC) [34][35][36], HPLC [12,[37][38][39][40][41], UPLC [42] and spectrophotometric [28,32,[43...…”

“…Of the various analytical methods mentioned above, the instruments required to determine QTF in pharmaceuticals by voltammetric [30,31], capillary zone electrophoretic [32,33], high performance thin layer chromatographic (HPTLC) [34][35][36], HPLC [12,[37][38][39][40][41] and UPLC [42] are highly sophisticated. Moreover, a highly skilful operator or an expertise is required to carry out the analysis.…”