Development studies of captopril certified reference material / Estudos de desenvolvimento de captopril material de referência certificado

This paper describes the studies performed with the candidate Certified Reference Material (CRM) of captopril, the first CRM of an active pharmaceutical ingredient (API) in Brazil, including determination of impurities (organic, inorganic and volatiles), homogeneity testing, short- and long-term stability studies, calculation of captopril content using the mass balance approach, and estimation of the associated measurement uncertainty.

Este artigo descreve os estudos realizados com o candidato a Material de Referência Certificado (MRC) de captopril, primeiro MRC de fármacos no Brasil, incluindo a determinação de impurezas (orgânicas, inorgânicas e voláteis), testes de homogeneidade, testes de estabilidade de curta e longa duração, cálculo do teor de captopril por balanço de massa e estimativa da incerteza de medição associada ao valor certificado.

Validation of a liquid chromatographic method for determination of related substances in a candidate certified reference material of captopril / Validação de um método cromatográfico líquido para a determinação de substâncias relacionadas, em um material candidato de referência certificado de captopril

This paper describes the validation of a reversed-phase high performance liquid chromatography method (RP-HPLC) with diode array detection (DAD) for determination of related substances (impurities from organic synthesis and degradation products) of captopril according to the Brazilian Pharmacopeia IV. The aim of this study was to guarantee the method accuracy for quantification of related substances, an essential requisite to determine, using the mass balance approach, the captopril content in the first Brazilian certified reference material (CRM) of an active pharmaceutical ingredient (API), developed by Inmetro. The captopril instability in solution is discussed and the captopril content determined by mass balance is compared to the results from titration and differential scanning calorimetry (DSC).

Este artigo descreve a validação de método de cromatografia líquida de alta eficiência em fase reversa (CLAE-RP) com detector de fotodiodos (DAD) para determinação de substâncias relacionadas (impurezas orgânicas de síntese e produtos de degradação) de captopril segundo Farmacopéia Brasileira IV ed. Este estudo teve como objetivo garantir que o método é capaz de quantificar com exatidão o teor de substâncias relacionadas, um requisito essencial para que o teor de captopril seja determinado por balanço de massa no primeiro material de referência certificado (MRC) de fármacos brasileiro, o qual foi desenvolvido pelo Inmetro. A instabilidade do captopril em solução é discutida em detalhes e o teor de captopril determinado por balanço de massa é comparado com aqueles obtidos por titulação e por calorimetria exploratória diferencial (DSC).

Development and validation of a column high-performance liquid chromatographic method for determination of sibutramine in capsules.

The development and validation of a reversed-phase liquid chromatographic (LC) method for the determination of sibutramine hydrochloride monohydrate in capsules is described. An isocratic LC analysis was performed on a reversed-phase RP-18 column (250 x 4.6 mm id, 5 microm particle size). The mobile phase consisted of methanol-water-triethylamine (80 + 20 + 0.5, v/v/v), with pH adjusted to 5.65 with 85% phosphoric acid, and was pumped at a constant flow rate of 1.0 mL/min. Measurements were made at a wavelength of 223 nm. The calibration curve was linear over the range of 15-40 microg/mL [correlation coefficient (r2) = 0.9998]. The relative standard deviation (RSD) value for intraday precision was 0.84%. The RSD value for interday precision was 0.90%. Recoveries ranged from 99.64 to 100.66%. No interferences from the excipients were observed. Because of its simplicity and accuracy, the method is suitable for routine quality control analysis of sibutramine in capsules.