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.

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 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.

Cetoconazol é um agente antifúngico, que pode ser incorporado em diferentes formas farmacêuticas, como, por exemplo, xampus e cremes. O objetivo do trabalho foi avaliar a segurança biológica in vivo (teste de irritação ocular) e in vitro (teste de citotoxicidade) do xampu de cetoconazol degradado sob ação da luz. Para tanto, a formulação foi exposta à radiação UV-C (254 nm) e foram empregados dois métodos para a determinação quantitativa do cetoconazol: CLAE e ensaio microbiológico. Os resultados demonstraram alteração do cetoconazol em presença da luz - presença de picos secundários no cromatograma e diminuição da atividade antifúngica - entretanto, não demonstraram alteração na segurança biológica entre xampu de cetoconazol e xampu de cetoconazol contendo produtos de degradação.

Ketoconazole is an antifungal agent and can be incorporated into several dosage forms, as an example it could be mentioned shampoos and creams. The aim of this work was to assess the biological reactivity in vivo (Draize eye test) and in vitro (cytotoxity test) of ketoconazole in shampoo degradeted under action of light. The formulation was exposed to UV-C (254 nm) radiation and two methods were used for the quantitative determination of ketoconazole: HPLC and microbiological assay. The results showed alteration in ketoconazole in presence of light - secondary peaks in chromatogram and decrease in antifungal activity - however, no alteration on the biological reactivity between ketoconazole shampoo and ketoconazole shampoo containing degradation products was observed.