EVALUATION OF THE STABILITY OF VIGABATRIN IN HOSPITALAR EXTEMPORANEOUS FORMULATIONS

The aim of this study was to analyze the chemical stability of the anticonvulsant vigabatrin extemporaneous formulation from tablets in storage conditions of different temperatures and types of packaging used. The analysis of vigabatrin extemporaneous formulations were performed by high-performance liquid chromatography (HPLC). The method described in British Pharmacopoeia was co-validated for specificity, linearity, precision and accuracy. Vigabatrin extemporaneous solutions were prepared in triplicate and placed in amber glass and PET bottles, which were stored under three different conditions: at room temperature (15 to 30 °C), under refrigeration (2 to 8 °C), and oven (40 °C). Samples of solutions stored at room temperature and refrigeration were collected every 7 days along 35 days. The same was done for solutions kept at 40 °C, but for a period of 28 days. It was also analyzed the solutions pH in each sampling time. Vigabatrin extemporaneous solutions showed variations within the limits of British Pharmacopoeia 2016 up to 21 days in amber PET and glass bottles at room and refrigerated temperatures. Vigabatrin content for formulations kept in oven decreased above 10% after 7 days of study. The lowest pH change occurred in amber glass bottle stored under refrigeration. Results of this study will be applied as a reference for vigabatrin extemporaneous formulation in hospital, once it was demonstrated the reliability of storage time interval and proper conditions for the use. Thus, pediatric patients with fractionated doses or use of nasogastric probe will have adequately prepared extemporaneous formulations, reducing the risk of dilution errors and microbiological contamination, improving the efficacy and safety, and enabling more time for nursing assistance. 

In vitro evaluation of cutaneous penetration of acyclovir from semisolid commercial formulations and relation with its effective antiviral concentration

The evaluation of drug permeation/penetration of semisolid formulations into animal skin can be useful to supplement the pharmaceutical equivalence. This paper describes the in vitro assessment of acyclovir (ACV) into porcine skin from commercial formulations with etermination of drug concentration in different layers of cutaneous tissue to correlate with effective antiviral concentration in order to improve the equivalence decision. Studies were conducted using Franz cells and porcine skin. Selected pharmaceutical creams containing ACV had identical (reference and generic) and different (similar) excipients. A software program was employed for the simulation of antiviral effectiveness in the skin. Regarding ACV skin penetration, the first batch of the generic product showed a significant difference from reference and similar products, while in the second batch all products demonstrated equivalent drug penetration in the skin. Simulation studies suggest that formulations analysed exhibit a pharmacological effect even when in contact with Herpes simplex strains of high IC50 (inhibitory concentration required to reduce viral replication by 50%). According to results, it can be assumed that the in vitro cutaneous permeation/penetration study does not supply sensitivity information regarding small alterations of ACV semisolid formulations due to the variability inherent to the method, although it can be relevant to pharmaceutical equivalence studies in the development of semisolid products

Second-derivative spectrophotometry for the analysis of simvastatin in polymeric nanocapsules

Conventional spectrophotometry methods are very susceptible to the presence of interferences in complex mixtures such as nanoparticules, requiring prior treatment or extraction of the analyte, and not always providing an adequate response. Derivative spectrophotometry method is capable to eliminate its interference; it is an alternative method for drugs determination in complex matrices. This work investigated the utility of derivate spectrophotometry in assay of simvastatin in polymeric nanocapsules (SIVNC). Shimadzu® UV-1650 double-beam spectrophotometer with 1.0 cm quartz cells was used in this study. The second-order deriva­tive spectrum was obtained employing Δλ=20,000 nm and scaling factor=9.0. The determinations were made at 239 nm (2D239) by zero-crossing method. 2D239 method was validated employing the parameters: specificity, linearity, robustness, precision and accuracy. Results: The specificity test showed there was no interference of constituents commonly found in SIVNC formulation in 2D239. The standard curve showed a correlation coefficient of 0.994. The robustness was evaluated by small changes in the conditions of sample analysis and however, no significant changes were observed regarding drug quantitation. The precision was demonstrated by relative standard deviation (RSD) of intra-day (RSD=1.61-3.76) and inter-day studies (RSD=2.32). The recovery test resulted in an average of 100.66%, which confirmed the accuracy of the method. The procedure was simple and rapid; therefore this technique offers an alternative for determination of SIVNC without interferences

In vitro toxic evaluation of two gliptins and their main impurities of synthesis

Background: The presence of impurities in some drugs may compromise the safety and efficacy of the patient’s treatment. Therefore, establishing of the biological safety of the impurities is essential. Diabetic patients are predisposed to tissue damage due to an increased oxidative stress process; and drug impurities may contribute to these toxic effects. In this context, the aim of this work was to study the toxicity, in 3 T3 cells, of the antidiabetic agents sitagliptin, vildagliptin, and their two main impurities of synthesis (S1 and S2; V1 and V2, respectively). Methods: MTT reduction and neutral red uptake assays were performed in cytotoxicity tests. In addition, DNA damage (measured by comet assay), intracellular free radicals (by DCF), NO production, and mitochondrial membrane potential (ΔψM) were evaluated. Results: Cytotoxicity was observed for impurity V2. Free radicals generation was found at 1000 μM of sitagliptin and 10 μM of both vildagliptin impurities (V1 and V2). A decrease in NO production was observed for all vildagliptin concentrations. No alterations were observed in ΔψM or DNA damage at the tested concentrations. Conclusions: This study demonstrated that the presence of impurities might increase the cytotoxicity and oxidative stress of the pharmaceutical formulations at the concentrations studied

Análise quantitativa de duloxetina e 1-naftol por cromatografia eletrocinética micelar

A duloxetina (DLX) é um inibidor seletivo da recaptação de serotonina e noradrenalina, usualmente utilizado no tratamento do transtorno depressivo maior. 1-Naftol (NPH) é uma impureza tóxica produzida quando o fármaco é exposto ao meio ácido e também procedente do material de síntese da DLX. Um método indicativo de estabilidade foi desenvolvido e validado por cromatografia eletrocinética micelar para determinação simultânea de DLX e NPH, utilizando cimetidina como padrão interno. As análises foram feitas em capilar de sílica fundida (40 cm comprimento efetivo). Os melhores resultados foram encontrados com um eletrólito composto por Tris e SDS, pH ajustado em 10,6, temperatura do capilar de 25 °C e voltagem aplicada de 25 kV. As amostras injetadas por força hidrodinâmica de 50 mbar durante 5 s, as detecções foram realizada por detector de fotodiodo ajustado em 231 nm. O método demonstrou-se linear, com r=0.9999 para DLX e NPH. A seletividade do método foi determinada pela análise do placebo da DLX e de sua exposição a meios de degradação. Nenhuma interferência foi verificada. O método proposto foi desenvolvido e validado com sucesso para a análise quantitativa de DLX e NPH, sendo sensível, preciso, exato e robusto, podendo assim ser aplicado no controle de qualidade da DLX e para assegurar que o NPH não ultrapasse as quantidades limites.Duloxetine (DLX) is a selective orally administered serotonin and norepinephrine reuptake inhibitor usually used in the treatment of major depressive disorder. 1-Naphthol (NPH) is a toxic impurity produced when the drug is exposed to acid medium and also it proceeds from the synthesis material. A simple and rapid stability indicating micellar electrokinetic chromatography method was developed and validated for the simultaneous determination of DLX and NPH, using cimetidine as internal standard. The method was performed with a fused-silica capillary (effective length: 40 cm). Optimum results were obtained with Tris and SDS background electrolyte at pH 10.6, capillary temperature of 25 °C and applied voltage of 25 kV. The samples were injected hydrodynamically for 5 s at 50 mbar and detections were done by photodiode array detector set at 231 nm. The selectivity was performed through the analysis of the DLX placebo solution and the exposition to degradation media. No interference in the DLX migration was verified. The linearity of the method obtained r=0.9999 for both molecules. Also, adequate results for accuracy, limits of detection and quantification, precision and robustness were obtained. The proposed method was successfully applied for the quantitative analysis of DLX and NPH. The developed method can be applied to routine quality control of DLX and to assure that the NPH do not exceed the allowed amounts

Análise quantitativa de duloxetina e 1-naftol por cromatografia eletrocinética micelar

A duloxetina (DLX) é um inibidor seletivo da recaptação de serotonina e noradrenalina, usualmente utilizado no tratamento do transtorno depressivo maior. 1-Naftol (NPH) é uma impureza tóxica produzida quando o fármaco é exposto ao meio ácido e também procedente do material de síntese da DLX. Um método indicativo de estabilidade foi desenvolvido e validado por cromatografia eletrocinética micelar para determinação simultânea de DLX e NPH, utilizando cimetidina como padrão interno. As análises foram feitas em capilar de sílica fundida (40 cm comprimento efetivo). Os melhores resultados foram encontrados com um eletrólito composto por Tris e SDS, pH ajustado em 10,6, temperatura do capilar de 25 °C e voltagem aplicada de 25 kV. As amostras injetadas por força hidrodinâmica de 50 mbar durante 5 s, as detecções foram realizada por detector de fotodiodo ajustado em 231 nm. O método demonstrou-se linear, com r=0.9999 para DLX e NPH. A seletividade do método foi determinada pela análise do placebo da DLX e de sua exposição a meios de degradação. Nenhuma interferência foi verificada. O método proposto foi desenvolvido e validado com sucesso para a análise quantitativa de DLX e NPH, sendo sensível, preciso, exato e robusto, podendo assim ser aplicado no controle de qualidade da DLX e para assegurar que o NPH não ultrapasse as quantidades limites.Duloxetine (DLX) is a selective orally administered serotonin and norepinephrine reuptake inhibitor usually used in the treatment of major depressive disorder. 1-Naphthol (NPH) is a toxic impurity produced when the drug is exposed to acid medium and also it proceeds from the synthesis material. A simple and rapid stability indicating micellar electrokinetic chromatography method was developed and validated for the simultaneous determination of DLX and NPH, using cimetidine as internal standard. The method was performed with a fused-silica capillary (effective length: 40 cm). Optimum results were obtained with Tris and SDS background electrolyte at pH 10.6, capillary temperature of 25 °C and applied voltage of 25 kV. The samples were injected hydrodynamically for 5 s at 50 mbar and detections were done by photodiode array detector set at 231 nm. The selectivity was performed through the analysis of the DLX placebo solution and the exposition to degradation media. No interference in the DLX migration was verified. The linearity of the method obtained r=0.9999 for both molecules. Also, adequate results for accuracy, limits of detection and quantification, precision and robustness were obtained. The proposed method was successfully applied for the quantitative analysis of DLX and NPH. The developed method can be applied to routine quality control of DLX and to assure that the NPH do not exceed the allowed amounts

Desenvolvimento e validação de métodos analíticos e estudos de estabilidade da rivaroxabana

A análise de fármacos é fundamental nas diversas fases do desenvolvimento farmacêutico, tais como estudos de formulação, estabilidade e controle de qualidade do produto. A rivaroxabana (RIV) é um anticoagulante de uso oral indicado para prevenção da formação de coágulos venosos. A literatura pesquisada apresenta poucos relatos de determinação quantitativa e de estudos de estabilidade do fármaco em comprimidos. E ainda nenhum método analítico em compêndios oficiais Diante do exposto, o objetivo deste trabalho foi desenvolver e validar métodos analíticos para determinação qualitativa e quantitativa da RIV por cromatografia líquida de alta eficiência com detecção por UV e de ultra eficiência com detecção por espectrometria de massas (CLAE-UV e CLUE-EM) e eletroforese capilar (EC). Os resultados encontrados foram adequados conforme o preconizado nos guias oficiais nacionais e internacionais. Foi avaliada também a viabilidade da técnica de eletroforese capilar em microchip para análise de RIV. Através de método desenvolvido por CLAE foi realizado estudo de cinética de degradação e posterior avaliação do potencial tóxico in vitro das amostras de degradação forçada da RIV. A identificação de três produtos de degradação majoritários da RIV, formados a partir de estresse ácido, alcalino e fotolítico, foi realizada por CLUE-EM/EM, possibilitando a proposição da estrutura molecular de cada produto de degradação. O potencial tóxico da RIV antes e depois da exposição à degradação forçada foi avaliado através dos métodos in vitro MTT, Vermelho Neutro, Ensaio Cometa e DNA de baixo peso molecular. Não foram encontrados sinais de dano ao DNA celular, contudo, amostras de RIV expostas ao meio alcalino apresentaram maior redução da viabilidade celular. O trabalho avaliou ainda o perfil de dissolução da RIV em comprimidos baseado nos dados de absorção in vitro conforme modelagem in silico dos dados, estabelecendo uma correlação linear entre a fração absorvida e fração dissolvida. As diferentes metodologias e técnicas desenvolvidas e aplicadas nesse trabalho contribuem para o desenvolvimento do controle de qualidade farmacêutico na direção de ensaios mais confiáveis que garantam a segurança e eficácia de medicamentos.Drug analysis is critical at various stages of pharmaceutical development, such as formulation studies, stability and quality control products. Rivaroxaban (RIV) is an oral anticoagulant indicated for prevention of thromboembolism. Literature contains few reports of quantitative determination and drug stability studies of RIV on pharmaceutical formulation. Analytical method for RIV quality control are not evaluable on official guides yet. This research work aimed to develop and validate analytical methods for qualitative and quantitative determination of RIV by high and ultra performance liquid chromatography with UV detection mass spectrometry detection (HPLC -UV and UPLC-MS) and capillary electrophoresis (CE). The results were adequate as recommended in national and international official guides. Reliability of RIV analysis by microchip capillary electrophoresis was also assessed. Through the method developed by HPLC degradation kinetic studies were performed, zero order kinetic has better description of RIV degradation behaviour. RIV toxic potential before and after exposure to forced degradation was assessed by in vitro methods of MTT, Neutral Red, Comet Assay, and Low Molecular Weight DNA. There were no signals of DNA damage however, RIV samples exposed to alkaline medium showed increased reduction in cell viability. Identification of RIV degradation products formed after exposure to acid and alkaline media and UVC radiation was performed by UPLC-MS / MS. It was possible to elucidate molecular structures of three major degradation products. This study also assessed the dissolution profile of RIV tablets based on in vitro absorption data, a linear point-to-point correlation was found for fraction absorbed and dissolved. Different methodologies and techniques developed and applied in this work can contribute to the development of pharmaceutical quality towards more reliable tests to ensure safety and efficacy of medicines

Desenvolvimento e validação de métodos analíticos e estudos de estabilidade da rivaroxabana

A análise de fármacos é fundamental nas diversas fases do desenvolvimento farmacêutico, tais como estudos de formulação, estabilidade e controle de qualidade do produto. A rivaroxabana (RIV) é um anticoagulante de uso oral indicado para prevenção da formação de coágulos venosos. A literatura pesquisada apresenta poucos relatos de determinação quantitativa e de estudos de estabilidade do fármaco em comprimidos. E ainda nenhum método analítico em compêndios oficiais Diante do exposto, o objetivo deste trabalho foi desenvolver e validar métodos analíticos para determinação qualitativa e quantitativa da RIV por cromatografia líquida de alta eficiência com detecção por UV e de ultra eficiência com detecção por espectrometria de massas (CLAE-UV e CLUE-EM) e eletroforese capilar (EC). Os resultados encontrados foram adequados conforme o preconizado nos guias oficiais nacionais e internacionais. Foi avaliada também a viabilidade da técnica de eletroforese capilar em microchip para análise de RIV. Através de método desenvolvido por CLAE foi realizado estudo de cinética de degradação e posterior avaliação do potencial tóxico in vitro das amostras de degradação forçada da RIV. A identificação de três produtos de degradação majoritários da RIV, formados a partir de estresse ácido, alcalino e fotolítico, foi realizada por CLUE-EM/EM, possibilitando a proposição da estrutura molecular de cada produto de degradação. O potencial tóxico da RIV antes e depois da exposição à degradação forçada foi avaliado através dos métodos in vitro MTT, Vermelho Neutro, Ensaio Cometa e DNA de baixo peso molecular. Não foram encontrados sinais de dano ao DNA celular, contudo, amostras de RIV expostas ao meio alcalino apresentaram maior redução da viabilidade celular. O trabalho avaliou ainda o perfil de dissolução da RIV em comprimidos baseado nos dados de absorção in vitro conforme modelagem in silico dos dados, estabelecendo uma correlação linear entre a fração absorvida e fração dissolvida. As diferentes metodologias e técnicas desenvolvidas e aplicadas nesse trabalho contribuem para o desenvolvimento do controle de qualidade farmacêutico na direção de ensaios mais confiáveis que garantam a segurança e eficácia de medicamentos.Drug analysis is critical at various stages of pharmaceutical development, such as formulation studies, stability and quality control products. Rivaroxaban (RIV) is an oral anticoagulant indicated for prevention of thromboembolism. Literature contains few reports of quantitative determination and drug stability studies of RIV on pharmaceutical formulation. Analytical method for RIV quality control are not evaluable on official guides yet. This research work aimed to develop and validate analytical methods for qualitative and quantitative determination of RIV by high and ultra performance liquid chromatography with UV detection mass spectrometry detection (HPLC -UV and UPLC-MS) and capillary electrophoresis (CE). The results were adequate as recommended in national and international official guides. Reliability of RIV analysis by microchip capillary electrophoresis was also assessed. Through the method developed by HPLC degradation kinetic studies were performed, zero order kinetic has better description of RIV degradation behaviour. RIV toxic potential before and after exposure to forced degradation was assessed by in vitro methods of MTT, Neutral Red, Comet Assay, and Low Molecular Weight DNA. There were no signals of DNA damage however, RIV samples exposed to alkaline medium showed increased reduction in cell viability. Identification of RIV degradation products formed after exposure to acid and alkaline media and UVC radiation was performed by UPLC-MS / MS. It was possible to elucidate molecular structures of three major degradation products. This study also assessed the dissolution profile of RIV tablets based on in vitro absorption data, a linear point-to-point correlation was found for fraction absorbed and dissolved. Different methodologies and techniques developed and applied in this work can contribute to the development of pharmaceutical quality towards more reliable tests to ensure safety and efficacy of medicines