Amazonia Products in Novel Lipid Nanoparticles for Fucoxanthin Encapsulation.

Lipid nanoparticles (LNs) are traditional systems able to effectively increase skin hydration. However, due to its reduced viscosity, LNs suspensions are less attractive for skin administration. To overcome this disadvantage, the LN were incorporated in the semi-solid formulation is easy manipulation. This study demonstrated that it is possible to obtain novel LN-loaded fucoxanthin (LN-FUCO) for topical administration containing a combination of bacuri butter and tucumã oil prepared by high shear homogenization for improved stability. The particle size was found to be 243.0 nm and the entrapment efficiency up to 98% of FUCO was incorporated and achieved the suitability of formula. The LN-FUCO hydrogel characteristics of slight acidity, drug content near 100%, and nanometric mean size assure to this formulation high compatibility to dermal application. Photostability assay by UVA, LN-FUCO, and LN-FUCO hydrogel improved photostability and conferred greater protection against FUCO degradation. The results obtained from in vitro skin permeation studies presented a significant difference between LN-FUCO hydrogel and FUCO (p < 0.05), with no detection of the drug in the receptor medium. Therefore, high shear homogenization is demonstrated to be a simple, available, and effective method to prepare high-quality LN-FUCO hydrogel for topical application.

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.

HPLC method for simultaneous analysis of ticagrelor and its organic impurities and identification of two major photodegradation products.

A simple, fast and sensitive analytical method by high-performance liquid chromatography (HPLC) was developed and validated for the simultaneous determination of ticagrelor and two synthesis impurities. The HPLC method was established using an Agilent 1200 Series equipment coupled to photodiode array detector (PDA) at 270nm with a Zorbax Plus C8 column (150×4.6mm, 5.0µm), injection volume of 20µL, and a constant temperature of 25°C. The mobile phase consisted of acetonitrile: ammonium acetate 50mM (57:43, v/v) and pH adjusted to 8.2 with ammonium hydroxide 6M, at a flow rate of 0.7mL/min. No interference peaks from excipients and diluent system indicated the specificity of the method. The calibration curves showed determination coefficients (r2)>0.99, calculated by linear regression. The limit of quantitation (LOQ) for impurities 1 and 2 were 2.0 and 0.2µg/mL, respectively. Intra and interday relative standard deviations (RSDs) were <2% for ticagrelor and <6% for the impurities, proving the precision of the method. Besides, two mayor degradation products formed when sample solutions of ticagrelor were exposed to UVC radiation were elucidated and the mechanisms involved in the photolytic degradation of ticagrelor were proposed.

Structural elucidation of gemifloxacin mesylate degradation product.

Gemifloxacin mesylate (GFM), chemically (R,S)-7-[(4Z)-3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl]-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate, is a synthetic broad-spectrum antibacterial agent. Although many papers have been published in the literature describing the stability of fluorquinolones, little is known about the degradation products of GFM. Forced degradation studies of GFM were performed using radiation (UV-A), acid (1 mol L(-1) HCl) and alkaline conditions (0.2 mol L(-1) NaOH). The main degradation product, formed under alkaline conditions, was isolated using semi-preparative LC and structurally elucidated by nuclear magnetic resonance (proton - (1) H; carbon - (13) C; correlate spectroscopy - COSY; heteronuclear single quantum coherence - HSQC; heteronuclear multiple-bond correlation - HMBC; spectroscopy - infrared, atomic emission and mass spectrometry techniques). The degradation product isolated was characterized as sodium 7-amino-1-pyrrolidinyl-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylate, which was formed by loss of the 3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl ring and formation of the sodium carboxylate. The structural characterization of the degradation product was very important to understand the degradation mechanism of the GFM under alkaline conditions. In addition, the results highlight the importance of appropriate protection against hydrolysis and UV radiation during the drug-development process, storage, handling and quality control.

Ultraviolet spectrophotometric method for analytical determination of mianserin hydrochloride in coated tablets and comparison with LC

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.

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.

Determination of quinolones and fluoroquinolones, tetracyclines and sulfonamides in bovine, swine and poultry liver using LC-MS/MS.

Antibacterials are widely used in veterinary medicine. Residues of these drugs can remain in food of animal origin, including bovine liver. This paper describes a fast and simple analytical method for the determination of quinolones and fluoroquinolones, tetracyclines and sulfonamides in bovine liver samples. Deuterated enrofloxacin, sulfapyridine and demeclocycline were used as internal standards. The homogenised liver samples were extracted with acidified acetonitrile. Steps of non-solid-phase extraction (SPE) clean-up and concentration were used in the presented method. The final extracts were analysed by sensitive and selective detection of all components in a single run using LC-MS/MS. Acceptable recoveries between 66% and 110% were obtained. Good linearity (r(2)) above 0.96, considering three different days, for all drugs was achieved in concentrations ranging from 0.0 to 2.0 × the maximum residue limit (MRL). Intraday precision with coefficient of variation (CV%) (n = 6) lower than 14.7% and inter-day precision lower than 18.8% in agreement with European Commission Decision 2002/657/EC were obtained in concentrations ranging from 0.5 to 1.5 MRL. Accuracy was between 86% and 110%. Limits of detection and quantitation, as well as decision limit (CCα) and detection capability (CCß), were also evaluated.

A simple, fast and cheap non-SPE screening method for antibacterial residue analysis in milk and liver using liquid chromatography-tandem mass spectrometry.

In routine laboratory work, screening methods for multiclass analysis can process a large number of samples in a short time. The main challenge is to develop a methodology to detect as many different classes of residues as possible, combined with speed and low cost. An efficient technique for the analysis of multiclass antibacterial residues (fluoroquinolones, tetracyclines, sulfonamides and trimethoprim) was developed based on simple, environment-friendly extraction for bovine milk, cattle and poultry liver. Acidified ethanol was used as an extracting solvent for milk samples. Liver samples were treated using EDTA-washed sand for cell disruption, methanol:water and acidified acetonitrile as extracting solvent. A total of 24 antibacterial residues were detected and confirmed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), at levels between 10, 25 and 50% of the maximum residue limit (MRL). For liver samples a metabolite (sulfaquinoxaline-OH) was also monitored. A validation procedure was conducted for screening purposes in accordance with European Union requirements (2002/657/EC). The detection capability (CCß) false compliant rate was less than 5% at the lowest level for each residue. Specificity and ruggedness were also discussed. Incurred and routine samples were analyzed and the method was successfully applied. The results proved that this method can be an important tool in routine analysis, since it is very fast and reliable.

Micellar electrokinetic chromatographic method for mianserin hydrochloride and analysis of degradation products by mass spectrometry.

A simple, stability-indicating micellar electrokinetic chromatography (MEKC) method was developed and validated for the analysis of mianserin hydrochloride in coated tablets. The method employed (hydroxymethyl)aminomethane (TRIS) 50 mM to which sodium dodecyl sulfate (SDS) 50 mM was added at pH 10.6 as the electrolyte and the voltage applied was 25 kV. The capillary used was 48.5 cm long (40.0 cm effective length and 50.0 µm i.d.) and the detection wavelength was 220 nm. Tetracycline was used as internal standard. The method was validated in accordance with the International Conference on Harmonization (ICH) requirements, which involved specificity, linearity, precision, accuracy and robustness. The stability-indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using photodiode array detection. The degradation products formed under photolytic and oxidative conditions were investigated by electrospray ionization mass spectrometry. The method was linear over the concentration range of 50-130 µg/mL. The method was precise as demonstrated by an inter-day and intra-day relative standard deviation of less than 2.0%. The proposed validated MEKC method showed recoveries between 98.16 and 102.80% of the nominal contents. The Plackett-Burman design was applied for the robustness test in order to examine potential sources of variability by screening a large number of factors in a relatively small number of experiments.

Identification, characterization and cytotoxicity in vitro assay of nitazoxanide major degradation product.

Stress studies of the broad-spectrum antiparasitic nitazoxanide were conducted in order to isolate and elucidate the major degradation product involved in thermal, acid, alkaline, oxidative and photolytic decomposition of the drug in solution and solid state. The major degradation product was identified and characterized using techniques namely LC-DAD, (1)H NMR, (13)C NMR, IR, and MS/MS. The stability of nitazoxanide raw material and nitazoxanide in tablets and in suspension powder was studied under different conditions and the results suggest the formation of the same deacetylated degradation product occur in all cases. This product was also studied in order to determine the preliminary cytotoxicity in vitro with mononuclear cells. Compared with nitazoxanide, the degradation product showed a higher cytotoxicity at a concentration of 40 µg mL(-1) after 48 h of incubation, under tested conditions. Therefore, stress studies showed that special care must be taken during the preparation, manufacture, and storage of this pharmaceutical drug.

Isolation and structure elucidation of photodegradation products of fexofenadine.

The photostability of the antihistamine fexofenadine hydrochloride is described. The stress studies revealed the photostability of the drug as the most adverse stability factor. The main photodegradation products were isolated and its structures were elucidated by 1H, 13C, COSY, HSQC, HMBC NMR and mass spectrometry techniques. The drug was exposed to UVC light at 254 nm in methanolic solutions and the degradation was followed by HPLC and TLC. The photostability of fexofenadine tablets was studied and the same degradation products were observed. The two photodegradation products isolated were characterized as the isopropyl derivative, obtained by decarboxilation of fexofenadine, and a benzophenone compound, which was obtained by rearrangement of aromatic rings and oxidation reactions. The results show the importance of appropriate light protection during the drug development process, storage and handling.

Determinação da segurança biológica do xampu de cetoconazol: teste de irritação ocular e avaliação do potencial de citotoxicidade in vitro / Determination of the biological reactivity of ketoconazole in shampoo: draize eye test and cytotoxity test

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.

Análise citotóxica de esparfloxacino e seus produtos de degradação em células mononucleares humanas / Cytotoxic activity of sparfloxacin and its degradation products in mononuclear human blood cells

O esparfloxacino (SPAX) é uma fluoroquinolona antibacteriana de amplo espectro e apresenta potente atividade contra bactérias gram-positivas, incluindo Streptococcus pneumoniae e Staphylococcus aureus inclusive cepas meticilina resistentes (MRSA), bactérias gram-negativas, não fermentadoras de glicose, anaeróbios, Legionella spp; Mycoplasma spp; Chlamydia spp e Mycobacterium spp. Uma importante característica desta classe de antimicrobianos é a fototoxicidade. Esparfloxacino tem sido estudado quanto às suas atividades terapêuticas, entretanto poucos métodos de análise são descritos na literatura. Este trabalho objetivou a determinação dos efeitos citotóxicos de esparfloxacino substância de referência (SPAX-SR), esparfloxacino comprimidos (SPAX-COMP), esparfloxacino comprimidos submetidos à luz por 36 horas (SPAX-COMP.36), e dois produtos (7 e 9) isolados após a fotodegradação de esparfloxacino sob luz UV-C nas concentrações de 31,25; 62,5; 125 e 250 µg/mL, sobre o cultivo in vitro de células mononucleares humanas. Os resultados, analisados estatisticamente pelo Teste de Tukey demonstraram que as soluções de esparfloxacino (SPAX-SR), SPAX-COMP e SPAX-COMP.36 em concentração de 250 µg/mL reduziram significativamente o número de células viáveis nestas condições. Este resultado não foi observado para as soluções das substâncias 7 e 9, o que sugere que estes produtos sejam menos citotóxicos do que o SPAX-SR, nas condições empregadas.

Performance characteristics of bioassay, UV-spectrophotometry and high performance liquid chromatographic determination of sparfloxacin in tablets

The microbiological bioassay, the UV-spectrophotometry and the high performance liquid chromatography (HPLC) methods for assaying sparfloxacin in tablets were compared. The accuracy, repeatability, and precision of each method was assessed and proved to be satisfactory. All methods were reliable within acceptable limits for antibiotic pharmaceutical preparations being accurate and precise. The microbiological bioassay and HPLC are more specific than UV-spectrophotometric analysis. Houwever, the microbiological bioassay requires 20 h to get results, and HPLC is the most expensive analysis. The application of each method as a routine analysis should be investigated considering cost, simplicity, equipment...

Esparfloxacino e as fluorquinolonas: uma revisäo de sua classificaçäo, atividade antibacteriana, mecanismo de açäo, características farmacocinéticas, tolerabilidade e perspectivas farmacêuticas / Sparfloxacin and the fluoroquinolones: a review of classification, antibacterial activity, mechanism of action, pharmacokinetic properties, tolerability and pharmaceutical perspectives

Foi realizada uma revisäo na literatura sobre as quinolonas, classe antibacteriana que possui amplo espectro de açäo, enfocando, principalmente, o esparfloxacino, fluorquinolona de terceira geraçäo que possui potente atividade contra bactérias Gram-positivas, como Streptococcus pneumoniae e Staphylococcus aureus inclusive cepas metilina resistentes (MRSA), bactérias Gram-negativas, anaeróbios, Legionella spp, Mycoplasma spp, Chlamydia spp e Mycobacterium spp.

Doseamento microbiológico do norflroxacino: método da difusäo em ágar (cilindros em placas) / Microbiological cilinder-plate assay method of norfloxacin

Sendo o norfloxacino um agente antimicrobiano recente e sendo o ensaio microbiológico de difusäo em ágar (cilindros em placas) muito utilizado na avaliaçäo da potência destes fármacos, os autores propuseram o método, utilizando o microorganismo Bacillus subtilis. Este novo ensaio baseia-se nos trabalhos microbiológicos existentes e pretende servir como referência para os ensaios físico-químicos a serem propostos. O método mostrou-se sensível e reprodutível na avaliaçäo da atividade percentual do norfloxacino

Doseamento físico-químico do norflocaxino espectrofotometria no ultravioleta / Psysical-chemistry assay method of norfloxacin: ultraviolet spectrophotometric assay method

Os autores propuseram o uso da espectrofotometria no ultravioleta, como método físico-químico para o doseamento em ágar (cilindros em placas). Este método mostrou boa sensibilidade e reprodutibilidade no doseamento de amostras recentes de norfloxacino

Doseamento físico-químico do norfloxacino: método espectrofotométrico do cloreto de ferro III / Psysical-chemistry assay method of norfloxacin: spectrophotometric assay method with iron (III) chloride

Os autores testaram um método alternativo para o doseamento do norfloxacino, através da espectrofotometria com cloreto de ferro III. O método baseia-se na formaçäo de um composto solúvel, de cor amarelo-alaranjada, entre o norfloxacino e o cloreto de ferro III. Analisou-se, também, a estabilidade do composto formado, a fim de determinar os limites de tempo para o ensaio. Os resultados obtidos para a amostra de norfloxacino foram satisfatórios, tendo como referência o ensaio microbiológico. Assim sendo, o doseamento com cloreto de ferro III é sensível, reprodutível e de fácil execuçäo

Doseamento físico-químico do norfloxacino: método espectrofotométrico do reativo de marquis / Physical-chemistry assay method of norfloxacin: spectrophotometric assay method with Marquis' reactive

Utilizou-se o reativo de Marquis para a padronizaçäo de um método espectrofotométrico de doseamento do norfloxacino. O composto formado, levemente amarelo, absorve a 410mm. Os autores analisaram também a estabilidade do composto formado, com o objetivo de fixar os limites de tempo para o ensaio. Empregou-se, como referência, o método microbiológico de difusäo em ágar (cilindros em placas). O método desenvolvido mostrou-se sensível e reprodutível