Development and validation of a rapid turbidimetric assay to determine the potency of norfloxacin in tablets

Norfloxacin is one of the first commercially available (and most widely used) fluoroquinolone antibiotics. This paper reports the development and validation of a simple, sensitive, accurate and reproducible turbidimetric assay method to quantify norfloxacin in tablets formulations in only 4 hours. The bioassay is based on the inhibitory effect of norfloxacin upon the strain ofStaphylococcus epidermidis ATCC 12228 IAL 2150 used as test microorganism. The assay was performed 3x3 parallel lines like, three tubes for each concentration of reference substance and three tubes for each sample concentration. The results were treated statistically by analysis of variance and were found to be linear (r2 = 0.9999) in the selected range of 25-100 μg mL-1; precise (intra-assay: relative standard deviation (RSD) = 1.33%; inter-assay: RSD = 0.21%), accurate (100.74%) and robust with RSD lower than 4.5%. The student's t-test showed no statistically significant difference between the proposed turbidimetric method and an HPLC method previously validated. However the turbidimetric assay can be used as a valuable alternative methodology for the routine quality control of this medicine, complementary to other physical-chemical methods.O norfloxacino foi a primeira fluorquinolona (e mais utilizada) disponível no mercado. Este trabalho divulga um novo desenvolvimento e validação de um método turbidimétrico simples, sensível, preciso e reprodutível para a quantificação de norfloxacino em comprimidos em apenas 4 horas. O bioensaio é baseado no efeito inibitório de norfloxacino sobre a cepa Staphylococcus epidermidis ATCC 12228 IAL 2150, utilizada como micro-organismo teste. O bioensaio foi efetuado através do delineamento de linhas paralelas 3x3, em que três tubos foram utilizados para a solução padrão e três tubos para as concentrações da amostra. Os resultados foram tratados estatisticamente pela análise de variância, apresentando coeficiente de correlação linear der2 = 0,9999, na faixa de 20 a 100 μg mL-1; precisão (intra-ensaio: desvio padrão relativo (RSD) 1,33%; inter-ensaio: RSD=0,21%), exatidão (100,74%) e robustez com RSD menor que 4,5%. O teste-tmostrou não haver diferença estatisticamente significativa entre o método turbidimétrico proposto e um método por HPLC previamente validado. No entanto, o ensaio turbidimétrico pode ser utilizado como método alternativo para o controle de qualidade de rotina para este antimicrobiano, como um complemento de outros métodos físico-químicos

A green approach for the quantification of daptomycin in pharmaceutical formulation by UV spectrophotometry

Daptomycin is the first approved drug from a new class of antimicrobials, the cyclic lipopeptides, and is a very important antimicrobial agent in current clinical practice. Currently, there are no "green" analytical methods described in the literature to analyze the typical pharmaceutical dosage form of daptomycin. Thus, the aim of this work was to validate an environment-friendly spectrophotometric method in the UV region, for the analysis of daptomycin as a lyophilized powder. Water was used as diluent and the analyses were carried out on a spectrophotometer at 221 nm. The method met all validation requirements of the ICH guidelines, over a concentration range of 6-21 µg mL-1. A Student's t-test demonstrated that the proposed method was comparable to an HPLC method previously validated. Thus, the validated spectrophotometric method could quantify daptomycin in a powder form for injectable solutions, while being an economical, rapid, and "green" alternative for routine analysis in quality control.A daptomicina é o primeiro membro aprovado de uma nova classe de antimicrobianos, os lipopeptídeos cíclicos, e é muito importante para a prática clínica atualmente. Não existem métodos analíticos "verdes" descritos na literatura para a análise da daptomicina na forma farmacêutica. Desta forma, o objetivo deste trabalho foi a validação de método espectrofotométrico na região do UV ambientalmente favorável para análise da daptomicina em pó liofilizado. A água foi escolhida como diluente e as análises foram realizadas em 221 nm. O método atendeu a todas as exigências de validação dos guias do ICH, na faixa de 6-21 µg mL-1. Teste t de Student mostrou que o método proposto é intercambiável com método de HPLC previamente validado. Assim, o método espectrofotométrico validado é capaz de quantificar a daptomicina em pó para solução injetável e é uma opção econômica, rápida e "verde" para análises de rotina do controle de qualidade deste fármaco

Stability-indicating RP-LC method for quantification of fusidic acid in cream

Fusidic acid is an antibiotic steroid indicated for the treatment of infections caused by the genus Staphylococcus, including methicillin resistant Staphylococcus aureus strains, and other Gram-positive bacteria. In the present study, a stability-indicating reversed-phase liquid chromatography (RP-LC) method was developed and validated for the determination of fusidic acid in dermatological cream as an alternative to existing methods. Analyses were performed using a C18 column and guard column at room temperature, eluting with an isocratic mobile phase of acetonitrile and water (72:28, v/v), adjusted to pH 3.5 with acetic acid, pumped at a flow rate of 1.0 mL min-1, detection at 210 nm and 20 µL of injection volume. The forced degradation study was conducted under acidic, alkaline, neutral, photolytic, and oxidative stress conditions. The method was validated according to ICH and FDA guidelines; it was linear, precise, accurate, selective, and robust over concentrations of 5-95 µg mL-1, with detection and quantification limits of 0.43 and 1.31 μg mL-1, respectively. Therefore, we conclude that this method is suitable for quantifying fusidic acid in pharmaceutical dermatological creams and determining its stability, representing a more economical and practical alternative for routine analysis in quality control

Validation of analytical methodology for quantification of cefazolin sodium pharmaceutical dosage form by high performance liquid chromatography to be applied for quality control in pharmaceutical industry

A reversed-phase high performance liquid chromatography method was validated for the determination of cefazolin sodium in lyophilized powder for solution for injection to be applied for quality control in pharmaceutical industry. The liquid chromatography method was conducted on a Zorbax Eclipse Plus C18 column (250 x 4.6 mm, 5 μm), maintained at room temperature. The mobile phase consisted of purified water: acetonitrile (60: 40 v/v), adjusted to pH 8 with triethylamine. The flow rate was of 0.5 mL min-1 and effluents were monitored at 270 nm. The retention time for cefazolin sodium was 3.6 min. The method proved to be linear (r2=0.9999) over the concentration range of 30-80 µg mL-1. The selectivity of the method was proven through degradation studies. The method demonstrated satisfactory results for precision, accuracy, limits of detection and quantitation. The robustness of this method was evaluated using the Plackett–Burman fractional factorial experimental design with a matrix of 15 experiments and the statistical treatment proposed by Youden and Steiner. Finally, the proposed method could be also an advantageous option for the analysis of cefazolin sodium, contributing to improve the quality control and to assure the therapeutic efficacy.Um método cromatográfico em fase reversa foi validado para a determinação de cefazolina sódica em pó liofilizado, a ser aplicado no controle de qualidade em indústrias farmacêuticas. O método por cromatografia líquida foi conduzido em coluna Zorbax Eclipse Plus C18 (250 × 4,6 mm, 5 µm) mantida à temperatura ambiente. A fase móvel consistiu de água purificada: acetonitrila (60 : 40 v/v), com o pH ajustado para 8 com trietilamina. A vazão usada foi de 0,5 mL min-1 e os analitos de interesse foram monitorizados a 270 nm. O tempo de retenção da cefazolina sódica foi de 3,6 min. As áreas dos picos de cefazolina sódica foram lineares na faixa de concentração de 30-80 µg mL-1 (r2 = 0,9999). A seletividade do método foi demonstrada através de estudos de degradação. O método demonstrou resultados satisfatórios para precisão, exatidão, limites de detecção e de quantificação. A robustez do método foi avaliada utilizando o esquema fatorial de Plackett-Burman com uma matriz de 15 experimentos simultâneos, e analisados por tratamento estatístico proposto por Youden e Steiner. Finalmente, o método proposto pode ser também uma opção de êxito para a análise de cefazolina sódica, contribuindo para o controle de qualidade e para garantir a eficácia terapêutica

Development and validation of UV spectrophotometric method for orbifloxacin assay and dissolution studies

New, simple and cost effective UV-spectrophotometric method was developed for the estimation of orbifloxacin in pharmaceutical formulation. Orbifloxacin was estimated at 290 nm in 0.5 M hydrochloric acid. Linearity range was found to be 1.0-6.0 μg mL-1. The method was tested and validated for various parameters according to main guidelines. The proposed method was successfully applied for the determination of orbifloxacin in tablets. The results demonstrated that the procedure is accurate, precise and reproducible, while being simple, economical and less time consuming. It can be suitably applied for the estimation of orbifloxacin in routine quality control and dissolution studies.Um método espectrofotométrico novo, simples e de baixo custo foi desenvolvido para a determinação de orbifloxacino em formulação farmacêutica. O orbifloxacino foi determinado em 290 nm utilizando ácido clorídrico 0,5 M como solvente. O intervalo de linearidade usado foi de 1,0 a 6,0 μg mL-1. O método foi testado e validado em vários parâmetros de acordo com os principais guias. O método proposto foi aplicado com sucesso para a determinação de orbifloxacino em comprimidos. Os resultados demonstraram que este procedimento é exato, preciso e reprodutível, ao mesmo tempo em que é simples, barato e de mais rápida execução e pode ser adequadamente aplicado para a determinação de orbifloxacino na rotina do controle de qualidade e em estudos de dissolução de comprimidos contendo este fármaco

A new and ecological miniaturized method by spectrophotometry for quantification of vancomycin in dosage form

Vancomycin, an important antibiotic, is marketed as lyophilized powder. In the context of routine analysis of this product, the existence of a more advantageous and effective method is interesting. Thus, the objective of this work is to develop and validate a new analytical method, faster, low-cost, ecological and miniaturized for quantification of vancomycin in lyophilized powder using spectrophotometry in ultraviolet region. Buffer solution pH 6.8, quartz cuvette with capacity of 700 µL and 280 nm were chosen. The method proved to be linear in the range of 50-150 µg/mL (0.9997). The selectivity of the method was proven in two ways: The standard-sample overlay aimed to identify vancomycin in the sample; The forced degradation test (sample solutions prepared in 0.01 M HCl, 0.01 M NaOH and aqueous conditions and kept at 60 ºC by 8 hours, and UV 254 nm at ambient temperature during 24 hours) aimed to show the susceptibility of the method to consequently indicate the stability of the sample. It was precise in intraday (RSD 1.27%), interday (RSD 1.18%) and between analysts (RSD 1.92%) levels. It was robust when small variations were performed in seven important parameters (wavelength, cuvette, filtration step, dibasic and monobasic phosphate brand, ultrasound time and source of water). The accuracy was proved by the standard recovery test and showed mean recovery of 101.10%. This method can be applied in routine analysis of quality control of vancomycin lyophilized powder and it is an effective, accessible and ecological alternative, which follows the Green Analytical Chemistry principles, presenting less waste generation, no use of toxic solvents, smaller sample volumes and required diluents, which impacts on the final cost of the analyzes

GREEN ANALYTICAL METHOD FOR QUANTIFICATION OF SECNIDAZOLE IN TABLETS BY HPLC-UV

A simple, rapid, economic and green analytical method was validated for the determination of secnidazole in tablets. The aim was to contribute to the green analytical chemistry since it has low use of organic solvent and low production of toxic waste. For the HPLC-UV method, the mobile phase was a mixture of purified water + 0.7 % acetic acid and ethanol (78:22, v/v), flow rate was 1.3 mL min-1 on column CN Phenomenex Luna (250 x 4.60 mm, 5 μm particle size), injection volume was 20 μL with UV detection at 318 nm and retention time of 4.26 minutes. The method was linear over the concentration range of 5-100 μg mL-1 (r = 0.9998) with limits of detection and quantitation of 0.533 e 1.615 μg mL-1, respectively. The precision of the method showed RSD less than 2 %. The accuracy determined by the average recoveries was 99.58 %. The secnidazole tablets were subjected to oxidation, acid, alkaline, neutral and photolysis degradation as stress conditions and the method was considered as indicative of stability. The method is adequate and safe to be a great alternative method in routine quality control analyzes for determination and quantification of secnidazole tablets

Quantitative analysis of pharmaceutical products by spectrophotometry in the infrared region: a practical review

Quality control in the chemical-pharmaceutical industry to identify and quantify the active ingredient has fundamental importance to guarantee the quality of the final product. Its lack can generate irreparable consequences, and therefore its existence is extremely important. However, currently, in this process there is an ecologically correct need beyond the choice of the ideal method and the ideal conditions. This mini-review contemplates the current technological vision of pharmaceutical analysis through Green Analytical Chemistry (GAC). Green and sustainable methods have a main focus providing economic, environmental and social benefits. An example is spectrophotometry in the infrared region for quantitative purposes. The purpose of this mini-review is to show a practical guide for the quantitative analysis of raw materials and pharmaceutical products by spectrophotometry in the infrared region in order to contribute to a sustainability cycle, where the guarantee of product quality and the analytical awareness about health, time, waste generation, environment and cost coexist. A practical review for quantitative analysis by spectrophotometry in the infrared region was shown. It is useful for routine analysis of pharmaceutical products in general, and it can be used by chemical-pharmaceutical laboratories around the world

DEVELOPMENT AND VALIDATION OF AN ECOLOGICAL, NEW AND RAPID STABILITY-INDICATING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR QUANTITATIVE DETERMINATION OF AZTREONAM IN LYOPHILIZED POWDER FOR INJECTION

Aztreonam is a monocyclic synthetic antimicrobial with bactericidal activity against Gram-negative bacteria, the first agent from the monobactam family to be therapeutically approved. It was developed and validated analytical method using high performance liquid chromatography with UV detection at 292 nm to quantify the aztreonam. Furthermore, assessing stability through stress tests was carried out. The chromatographic separation was carried out by reverse phase on an Agilent C18 column (250 x 4.6 mm, 5 µm) with a mobile phase composed of water:ethanol (70:30, v/v) adjusted to pH 2.5 with acetic acid, pumped isocratically at a flow rate of 0.5 mL/min. The validation parameters linearity, selectivity, precision, accuracy, robustness, limits of detection and quantification were determined. The method proposed provides linear response within the concentration range of 45-95 µg/mL for aztreonam. Results obtained were found to be satisfactory. The proposed method is linear, accurate, precise, selective, and robust being able to quantify the aztreonam in raw material and in pharmaceutical preparations. The validated method was suitable for applications in quality control laboratories

Development and validation of a microbiological assay for determination of chlorhexidine digluconate in aqueous solution

Chlorhexidine (CHX) is a broad-spectrum antiseptic that is used in many topical pharmaceutical formulations. Because there is no official microbiological assay reported in the literature that is used to quantify CHX, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method for the dosage of chlorhexidine digluconate (CHX-D) in an aqueous solution. The assay is based on the inhibitory effect of CHX-D upon the strain of Staphylococcus aureus ATCC 25923, which is used as the test microorganism. The design 3x3 parallel-line model was used. The results were treated statistically by analysis of variance (ANOVA), and they were excellent in terms of linearity (r = 0.9999), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 0.5 to 4.5%. The results obtained were precise, having relative standard deviations (RSD) for intra-day and inter-day precision of 2.03% and 2.94%, respectively. The accuracy was 99.03%. The method proved to be very useful and appropriate for the microbiological dosage of CHX-D in pharmaceutical formulations; it might also be used for routine drug analysis during quality control in pharmaceutical industries.Clorexidina (CHX) é um antisséptico com amplo espectro de ação utilizada em muitos tipos de preparações farmacêuticas para uso tópico. Uma vez que não há na literatura ensaio microbiológico oficial para quantificar a clorexidina, este trabalho objetivou o desenvolvimento e validação de um ensaio microbiológico simples, sensível, exato e reprodutível, por difusão em ágar, para doseamento de digliconato de clorexidina (CHX-D) em solução aquosa. O ensaio é baseado no efeito da inibição de Staphylococcus aureus ATCC 25923, utilizado como microorganismo teste, pela CHX-D. Utilizou-se o delineamento 3x3. Os resultados foram verificados estatisticamente pela análise de variância (ANOVA) e apresentaram excelente linearidade (r = 0,9999), demonstrando que o método segue o modelo linear com regressão significativa entre o diâmetro da zona de inibição e o lagaritmo da concentração no intervalo de 0,5 a 4,5%. Os resultados obtidos foram precisos apresentando desvio padrão relativo (DPR) para precisão intra-dia de 2,03% e DPR para precisão inter-dias de 2,94%. A exatidão foi 99,03%. O método provou ser muito útil e apropriado para doseamento microbiológico da CHX-D em formas farmacêuticas e pode ser empregado para análise desta substância no controle de qualidade em indústrias farmacêuticas