resumo Os métodos por espectrofotometria na região do ultravioleta (UV) e por cromatografia líquida (CL) para determinação do cloridrato de mianserina na forma farmacêutica foram desenvolvidos e validados. Os vários parâmetros, como especificidade, linearidade, precisão e exatidão foram avaliados de acordo com o International Conference on Harmonization (ICH, 2005). Para o método de UV, o cloridrato de mianserina foi determinado utilizando o comprimento de onda de 278 nm e HCl 0,1 M como solvente. A resposta foi linear na faixa de concentração de 20,0 a 140,0 µg/Ml (r = 0,9998). A precisão foi avaliada pelo valor de desvio padrão relativo (DPR) inferior a 2%. O método por UV é simples, rápido e de baixo custo. As análises cromatográficas foram realizadas em uma coluna Ace C18 e a fase móvel foi composta por metanol, tampão fosfato de potássio monobásico 50 mM com 0,3% de trietilamina com o pH ajustado para 7,0 com ácido fosfórico 10% (85:15). O método de CL foi específico, linear, preciso, exato e robusto. Os resultados confirmam que ambos os métodos são válidos e úteis para o controle de qualidade do cloridrato de mianserina em comprimidos revestidos. A análise estatística por teste t de Student não mostrou diferença significativa entre os resultados obtidos para os métodos de UV e CL.

abstract Ultraviolet spectrophotometric (UV) and Liquid Chromatographic (LC) methods for the determination of mianserin hydrochloride in pharmaceutical formulation were developed and validated. The various parameters, such as specificity, linearity, precision and accuracy were studied according to International Conference on Harmonization (ICH, 2005). For UV method, mianserin hydrochloride was determinate at 278 nm using HCl 0.1 M as the solvent. The response was linear in the concentration range of 20.0 - 140.0 µg/mL (r = 0.9998). Precision data evaluated by relative standard deviation was lower than 2%. The UV method was simple, rapid and low cost. Chromatographic analyses were performed in an Ace C18 column and the mobile phase was composed of methanol, 50 mM monobasic potassium phosphate buffer and 0.3% triethylamine solution adjusted to pH 7.0 with phosphoric acid 10% (85:15). LC method was specific, linear, precise, exact and robust. The results confirmed that the both methods are valid and useful to the routine quality control of mianserin hydrochloride in coated tablets. Statistical analysis by Student´s t-test showed no significant difference between the results obtained by UV and LC methods.

AbstractThis study uses high performance liquid chromatography and capillary electrophoresis as analytical tools to evaluate flavonoids in hydrolyzed leaves extracts of Rubus erythrocladus Mart., Rosaceae, and Morus nigra L., Moraceae. For phytochemical analysis, the extracts were prepared by acid hydrolysis and ultrasonic bath and analyzed by high performance liquid chromatography using an ultraviolet detector and by capillary electrophoresis equipped with a diode-array detector. Quercetin and kaempferol were identified in these extracts. The analytical methods developed were validated and applied. Quercetin and kaempferol were quantified in R. erythrocladus, with 848.43 ± 66.68 μg g-1 and 304.35 ± 17.29 μg g-1, respectively, by HPLC-UV and quercetin, 836.37 ± 149.43 μg g-1, by CE-DAD. In M. nigra the quantifications of quercetin and kaempferol were 2323.90 ± 145.35 μg g-1 and 1446.36 ± 59.00 μg g-1, respectively, by HPLC-UV and, 2552.82 ± 275.30 μg g-1 and 1188.67 ± 99.21 μg g-1, respectively, by CE-DAD. The extracts were also analyzed by ultra-performance liquid chromatography coupled with a diode-array detector and mass spectrometer (MS), UPLC-DAD/MS.

A stability-indicating method using MEKC was validated for the analysis of olmesartan medoxomil in tablets. Successful separation was achieved using a fused silica capillary (40 cm x 50 µm i.d.); background electrolyte consisted of a combination of 10 mmol L-1 borate buffer and 5 mmol L-1 anionic detergent sodium dodecyl sulfate (95:5; v/v) pH 6.5; hydrodynamic mode at 50 mBar for 5 s; 25 kV separation voltage at 25 ºC; and column temperature 25 ºC with detection at 257 nm. The proposed method, validated following ICH guidelines, was applied to the determination of this antihypertensive with good results compared with an LC method.

This study describes the validation of UV spectrophotometric method for quantitative determination of gemifloxacin mesylate (GFM) in tablets using methanol as solvent. The method was specific, linear, precise, exact and robust at 272 and 343 nm. The results confirmed that the method in both wavelengths is valid and useful to the routine quality control of GFM in coated tablets. The validate method was compared to liquid chromatography (HPLC), microbiological assay and visible (VIS) spectrophotometry, which were previously developed and validated to the same drug. There was not significative difference between the methods for GFM quantitation.

A finalidade deste estudo foi desenvolver e validar um método de dissolução para o fármaco lamotrigina na forma farmacêutica comprimido. Este método também foi utilizado para comparar o perfil de dissolução entre o Neural® e o produto de referência Lamictal®. O procedimento analítico foi realizado utilizando-se espectrofotometria de absorção no ultravioleta (267 nm) como forma de quantificação do fármaco. Após a determinação da solubilidade e das condições sink, os parâmetros selecionados foram: pás (50 rpm), 900 mL de ácido clorídrico 0.01 M e o tempo de 30 minutos (único ponto). Este método foi validado através da especificidade, linearidade, exatidão, precisão e robustez. A estabilidade da lamotrigina também foi avaliada no meio de dissolução.

A dissolution test for tablets containing 100 mg of lamotrigine was developed and validated. The dissolution test was applied to compare the dissolution profile of Neural® with the reference product Lamictal®. The analysis procedure was carried out using a simple ultraviolet method at 267 nm. After the determination of solubility and sink conditions, the parameters selected were paddles at 50 rpm, 900 mL of 0.01 M hydrochloric acid, and 30 minutes duration (single point). This method was validated for specificity, linearity, accuracy, precision and robustness. Lamotrigine stability was also evaluated in dissolution medium.

A rapid, economical, reproducible, and simple direct spectrophotometric method was developed and validated for the assay of nitazoxanide in pharmaceutical formulations. Nitazoxanide concentration was estimated in water at 345 nm and pH 4.5. The method was suitable and validated for specificity, linearity, precision, and accuracy. There was no interference of the excipients in the determination of the active pharmaceutical ingredient. The proposed method was successfully applied in the determination of nitazoxanide in coated tablets and in powders for oral suspension. This method was compared to a previously developed and validated method for liquid chromatography to the same drug. There was no significative difference between these methods for nitazoxanide quantitation.

A carbocisteína é um agente mucolítico utilizado como adjuvante no tratamento de infecções do trato respiratório. A qualidade, segurança e eficácia do medicamento durante o seu prazo de validade são responsabilidades da indústria farmacêutica. A validade pode ser determinada através de estudos de estabilidade acelerados, nos quais fatores extrínsecos provocam a degradação do produto. De acordo com Arrhenius, existe uma relação entre temperatura e cinética química. Desta forma, amostras do produto foram expostas a condições drásticas: 40, 50, 60 e 70 ºC. O método de doseamento do xarope de carbocisteína foi validado podendo ser aplicado nas avaliações de rotina do controle de qualidade e no estudo de estabilidade deste produto. O prazo de validade proposto para o xarope de carbocisteína, calculado através da equação de Arrhenius, para a temperatura de 25 ºC foi de 240,9 dias. No entanto, foi observada diferença entre o prazo proposto e a validade usualmente praticada para este produto. Este estudo, ainda, demonstrou a presença de picos endógenos, que precisam ser melhor estudados a fim de se confirmar a presença de produtos de degradação.

Carbocysteine is a mucolytic agent in adjunctive therapy of respiratory tract infections. The pharmaceutical industry is responsible for quality, safety and efficiency of the product during its shelf life. Shelf life can be determinated through an accelerated stability study where the degradation of the drug is managed with the extrinsic factors. According to Arrhenius, there is a relationship between temperature and chemical kinetic, so, the samples were exposed to drastic conditions at 40, 50, 60 and 70 ºC. The syrup assay method has been validated and it may be applied to analysis of carbocysteine syrup in routine quality control and stability studies. Through Arrhenius equation the proposed shelf life of carbocysteine syrup was 240.9 days when the dosage form is stored in appropriated conditions, 25 ºC. However difference was found between the proposed shelf life and the usual shelf life of this drug. In addition, this study has showed the presence of endogenous peaks that must be better evaluated to confirm or not the presence of degradation products.