Sensitive and rapid titrimetric and spectrophotometric methods for the determination of stavudine in pharmaceuticals using bromate-bromide and three dyes

Anais da Academia Brasileira de Ciências

Kanakapura Basavaiah²  Veeraiah Ramakrishna¹  Chikkaswamy Somashekar²  Urdigere R. Anil Kumar² 

[1] ,University of Mysore Department of ChemistryMysore ,India

关键词: Stavudine determination;    titrimetry;    spectrophotometry;    bromate-bromide;    dyes;    pharmaceuticals;    determinação de estavudina;    titulometria;    espectrofotometria;    bromato-brometo;    corantes;    fármacos;   

DOI  :  10.1590/S0001-37652008000200003

来源: SciELO

【 摘 要 】

Four sensitive and rapid methods for the determination of stavudine (STV) in bulk drug and in dosage forms were developed and optimized. In titrimetry, aqueous solution of STV was treated with a known excess of bromate-bromide in HCl medium followed by estimation of unreacted bromine by iodometric back titration. Spectrophotometric methods involve the addition of a measured excess of bromate-bromide in HCl medium and subsequent estimation of the residual bromine by reacting with a fixed amount of methyl orange, indigocarmine or thymol blue followed by measurement of absorbance at 520 nm (method A), 610 nm (method B) or 550 nm (method C). In all the methods, the amount of bromate reacted corresponds to the amount of STV. Calculations in titrimetry were based on a 1:0.666 (STV:KBrO3) stoichiometry and the method was found to be applicable over 3.5-10 mg range. A linear increase in absorbance with concentration of STV was observed in the spectrophotometric methods, and the Beer's law was obeyed over the concentration ranges 0.125-1.75, 1-10 and 1-9.0 µg mL-1 STV for method A, method B and method C, respectively. The methods when applied to the determination of STV in tablets and capsules were found to give satisfactory results.

【 授权许可】

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