A reversed-phase liquid chromatographic method was developed for the assay of synephrine in Citrus aurantium dry extract. The chromatographic separation used a C18 (250 × 4.6 mm, 5 µm) column and a mobile phase consisting of acetonitrile: 0.01% orthophosphoric acid (pH 3.0) at a 15:85 ratio, flow rate of 1 mL min -1 and detection at 220 nm. The detector response was linear in the range 15 - 45 mg mL -1 . Specificity and stability, indicating suitability of the method, were confirmed using stress conditions (acid and basic hydrolysis, oxidation and photolysis). Intraday precision yielded RSD values of less than 1.77% and interday precision of 2.5%. The average recovery accuracy of the test was 102.03%. The method was validated according to international guidelines and can be used in routine quality control and stability studies of Citrus aurantium preparations. The preliminary stability study showed that synephrine is susceptible to hydrolysis, oxidation and photolysis. ]]>
This study aimed to develop and validate a stability-indicating liquid chromatography method for the determination of tirofiban hydrochloride and two synthetic impurities (impurity A and impurity C). The method utilizes a RP-18 column (250 mm × 4.6 mm; 5 μm) with the PDA detector for quantitation. A mixture of triethylamine 0.1% (acidified to pH 5.5 with phosphoric acid) and acetonitrile was used as the mobile phase at a flow rate of 1 mL min−1 with gradient elution. The method presented satisfactory linearity, precision, accuracy and robustness, as well as low limits of detection and quantification, which demonstrate sensitivity in the determination of tirofiban and impurities A and C. It was selective for the determination of the drug and impurities analysed, without interference of the degradation products generated under forced conditions, demonstrating the stability-indicating capacity of the proposed method. Tirofiban showed to be practically stable to oxidative (30% H2O2 for 24 h) and thermal (75 ºC for 24 h) conditions, but presented degradation to UVA light and acid hydrolysis, obeying the first order kinetics for both. In this way, it can be used as a stability-indicating method in the quality control of the raw material of tirofiban hydrochloride, as well as of the finished product. The obtained results demonstrate the importance of deepening the studies in this area, in order to guarantee the quality of commercialized pharmaceutical products.
As ferramentas de tecnologia digitais da informação e comunicação vem sendo utilizadas como aliadas no ensino. O ensino de química por vezes necessita de atividades práticas em laboratórios para melhor elucidar o conteúdo, e utilizar vídeos voltados para esta abordagem podem auxiliar no processo de ensino aprendizagem. Este estudo, de caráter descritivo, qualitativo e quantitativo, tem por objetivo descrever a confecção de vídeos-manuais voltados ao manuseio de equipamentos em laboratórios de química, e analisar o alcance e a satisfação do material produzido e disponibilizado no canal “Projeto AQuí” no YouTube. O material didático foi elaborado por alunos de graduação, seguindo os passos de pré-produção, produção e pós produção descritos neste trabalho. Através dos indicadores obtidos pelo YouTube Analytics, foi possível verificar o alcance do material produzido, e através dos comentários deixados voluntariamente na página foi possível perceber a satisfação dos espectadores com o material. Com base nas métricas analisadas, o canal “Projeto AQuí” no YouTube cumpre sua proposta de divulgação de material sobre operações laboratoriais, com um alcance nacional e internacional, sendo utilizado por instituições de ensino técnico e de ensino superior. Palavras-chave: TDIC. Material didático. Tecnologia na educação. Vídeo. Equipamentos de laboratório.
This study describes the development and evaluation of stability-indicating liquid chromatographic (LC) and UV spectrophotometric methods for the quantification of ciprofibrate (CPF) in tablets and capsules. Isocratic LC separation was achieved on a RP 18 column using a mobile phase of o-phosphoric acid (0.1% v/v), adjusted to pH 3.0 with triethylamine (10% v/v) and acetonitrile (35:65 v/v), with a flow rate of 1.0 mL min -1 . Detection was achieved with a photodiode array detector at 233 nm. For the spectrophotometric analysis, ethanol and water were used as the solvent and a wavelength of 233 nm was selected for the detection. The methods were validated according to International Conference on Harmonization (ICH) guidelines for validating analytical procedures. Statistical analysis showed no significant difference between the results obtained by the two methods. The proposed methods were successfully applied to the CPF quality-control analysis of tablets and capsules.Uniterms: Ciprofibrate/tablets/quality control. Ciprofibrate/capsules/quality control. UV Spectrophotometry/quantitative analysis. Liquid chromatography/stability study. Medicines/quality control.Este estudo descreve o desenvolvimento e avaliação de método indicativo da estabilidade por cromatografia líquida (LC) e método por espectrofotometria UV para quantificação de ciprofibrato (CPF) em comprimidos e cápsulas. No método por cromatografia líquida as análises foram realizadas isocraticamente em coluna de fase reversa C18, utilizando fase móvel composta por ácido o-fosfórico (0.1% v/v) pH 3.0, ajustado com trietilamina (10% v/v), e acetonitrila (35:65 v/v), com fluxo de 1,0 mL min -1 . A detecção foi realizada em detector de arranjo de diodos a 233 nm. Na análise espectrofotométrica, etanol e água foram utilizados como solventes e o comprimento de onda de 233 nm foi selecionado para a detecção do fármaco. Os métodos foram validados de acordo com as diretrizes do International Conference on Harmonization (ICH). A análise estatística não mostrou diferença significativa entre os resultados obtidos pelos dois métodos. Os métodos foram aplicados com sucesso para análises de controle de qualidade do ciprofibrato em comprimidos e cápsulas.Unitermos: Ciprofibrato/comprimidos/controle de qualidade. Ciprofibrato/cápsulas/controle de qualidade. Espectrofotometria UV/análise quantitativa. Cromatografia líquida/estudo da estabilidade. Medicamentos/ controle de qualidade.
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