1,779 research outputs found

    Encapsulation of naproxen in nanostructured system: structural characterization and in vitro release studies

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    Nanoparticles were produced by solvent emulsification evaporation method with the following characteristics: nanometric size (238 ± 3 nm), narrow polydispersity index (0.11), negative zeta potential (-15.1 mV), good yield of the process (73 ± 1.5%), excellent encapsulation efficiency (81.3 ± 4.2%) and spherical shape. X-rays diffraction demonstrated the loss of drug crystallinity after encapsulation; however, the profile of the diffractograms of the poly-ε-caprolactone (PCL) nanoparticles was kept. Differential scanning calorimetry thermograms, correspondingly, exhibited the loss of drug melting peak and the increasing of the melting point of the PCL nanoparticles, evidencing an interaction drug-polymer. Naproxen release was low and sustained obeying the Higuchi´s kinetic. The results show that nanoparticles are promising sustained release system to the naproxen

    HPLC assay of lidocaine in in vitro dissolution test of the Poloxamer 407 gels

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    Apresenta-se método simples de cromatografia líquida de alta eficiência (CLAE) para análise da lidocaína em meio aquoso, após estudo de liberação in vitro. A lidocaína foi analisada usando-se coluna LichroCART RP-18 (5 mm, 125x4 mm), fase móvel constituída de acetonitrila: tampão fosfato de sódio 0,05 M, pH 6 (35:65), adicionada de 0,05% de dietilamina com fluxo de 1 mL/min. O tempo de retenção foi de 7,9 min. O comprimento de onda de análise utilizado foi de 210 nm. A linearidade do método foi de 1,25 a 25 µg/mL com coeficiente de variação intraensaio e inter-ensaio menor que 3,5 %. A metodologia desenvolvida e validada mostrou sensibilidade e especificidade para a realização dos estudos propostos, considerando-se que as amostras obtidas a partir dos estudos de liberação in vitro contêm concentrações muito baixas do fármaco, além de outras substâncias do meio de dissolução que podem interferir no doseamento. A quantificação do fármaco e dos interferentes pode não ser possível se for efetuada por outras metodologias analíticas convencionais. Assim, o método desenvolvido é de grande importância para a quantificação do fármaco nas alíquotas obtidas nos ensaios de liberação in vitro.A simple high performance liquid chromatography method to assay lidocaine hydrochloride in aqueous receiving media, following in vitro release, is presented. Lidocaine hydrochloride was analysed using a 5 mm LichroCART® RP-18 column (125 x 4 mm i.d.). The mobile phase was acetonitrile: 0.05 M sodium phosphate buffer, pH 6.0 (35:65) and 0.05% of diethylamine at a flow rate of 1 mL/min. The retention time was 7.9 min. Detection was carried out at 210 nm at room temperature (28 ºC). The method was found to be linear in the range 1.25 to 25 mg/mL, showing average intraassay and inter-assay coefficients of variation below 3.5%. The proposed method was validated for linearity, specificity, precision and accuracy and was shown to be useful for the analysis of lidocaine hydrochloride in in vitro release studies

    Improving the oral screening with optical fluorescence

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    A fluorescência óptica pode ser utilizada como um coadjuvante ao exame clínico bucal, uma vez que permite, por autofluorescência, a detecção de inúmeras alterações na cavidade bucal que poderiam passar despercebidas pelo cirurgião-dentista ou até mesmo de difícil percepção apenas pelo método visual. O objetivo do presente estudo foi demonstrar o uso do sistema de fluorescência óptica por imagem no diagnóstico de diferentes lesões da cavidade bucal, seja em tecido duro ou mole, de forma a familiarizar o cirurgião-dentista com o uso do equipamento. Para este estudo foi utilizado um equipamento constituído de um diodo emissor de luz (LED), com emissão na região do violeta e um conjunto de filtros ópticos (Evince - MMoptics, São Carlos, SP, Brasil). Para a aquisição das imagens foi acoplado ao equipamento uma câmera fotográfica (Nikon, D90, Bangkok, Tailândia) com o auxílio de um adaptador. O sistema de fluorescência bucal possibilitou observar alterações nos tecidos duros dentais como manchas, presença de placa e cálculo dental, lesões incipientes e infiltrações marginais, além de facilitar a diferenciação entre materiais restauradores como resina composta e cerâmica. Em tecidos moles foi possível detectar lesões potencialmente malignas e lesões tumorais. Portanto, pode--se concluir que o sistema de fluorescência óptica permite ao cirurgião-dentista diagnosticar e identificar estruturas e alterações na cavidade bucal de forma simples, não invasiva e em tempo real revelando lesões que não seriam facilmente detectados com a iluminação convencional.Fluorescence techniques can be used as an adjunct to clinical examination of the mouth, detecting tissue changes in oral mucosa or hard dental tissues, which might be unnoticed by the dentist or even difficult to detect under white light examination. The aim of this study was to demonstrate the use of wide-field fluorescence imaging in the diagnosis of various lesions of the oral cavity, either in hard or soft tissues, in order to familiarize the dentist with the use of the equipment. For this study we used an optical fluorescence system with emission in the violet region (Evince, MMOptics, São Carlos, SP, Brazil). For image acquisition, the fluorescence system was coupled to a digital camera (Nikon D90, Nikon, Bangkok, Tailândia). With the fluorescence system was possible to observe changes in hard dental tissues such as bright spots, dental plaque and calculus, incipient carious and marginal microleakage lesions. The system also facilitated the differentiation between restorative materials such as composite resin and ceramic. The fluorescence optical was also helpful in screening and detection of potentially malignant lesions and tumors could be observed. Therefore, we conclude that the fluorescence optical system allows the dentist to identify structures and alterations in the oral cavity in a simple, noninvasive, and in real-time procedure, revealing injuries that would not be easily detected with conventional illumination.FAPESPCNPqCAPESCEPID - CePOFInstituto Nacional de Ciência e Tecnologia de Óptica e Fotônica (INCT - INOF

    Preparation of extemporaneous oral liquid in the hospital pharmacy

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    At the hospital, the pharmacist is constantly challenged to prepare extemporaneous solutions from tablets, capsules or drug powder for patients unable to swallow, such as pediatric, elderly and patients that use nasoenteric and nasogastric tubes. The preparation of extemporaneous solutions from capsules, tablets and drug powder requires stability studies analysis. This article is a bibliographic review of preparation of extemporaneous oral liquid from solid oral dosage forms used in clinical practice. The selected articles contain all the information regarding manipulation techniques, pharmaceutical excipients, packaging, storage conditions and results of stability studies above 90% performed by HPLC analysis. In addition, a situational analysis of the strategies for the preparation of the extemporaneous solution was described to help the manipulator in the decision. The preparation of extemporaneous solution from solid oral dosage forms is based on information from official compendium or scientific literature, to ensure safe and effective manipulated medicine

    l-Tyrosine-loaded nanoparticles increase the antitumoral activity of direct electric current in a metastatic melanoma cell model

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    Inhibition of tumor growth induced by treatment with direct electric current (DC) has been reported in several models. One of the mechanisms responsible for the antitumoral activity of DC is the generation of oxidative species, known as chloramines. With the aim of increasing chloramine production in the electrolytic medium and optimizing the antitumoral effects of DC, poly(ɛ-caprolactone) (PCL) nanoparticles (NPs) loaded with the amino acid tyrosine were obtained. The physical–chemical characterization showed that the NPs presented size in nanometric range and monomodal distribution. A slightly negative electrokinetic potential was also found in both blank NPs and l-tyrosine-loaded PCL NPs. The yield of the loading process was approximately 50%. Within 3 h of dissolution assay, a burst release of about 80% l-tyrosine was obtained. The in vitro cytotoxicity of DC was significantly increased when associated with l-tyrosine-loaded NPs, using a murine multidrug-resistant melanoma cell line model. This study showed that the use of the combination of nanotechnology and DC has a promising antineoplastic potential and opens a new perspective in cancer therapy

    Development, characterization and evaluation of the dissolution profile of sulfasalazine suspensions

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    ;O trabalho reporta o desenvolvimento, caracterização e estudo ;in vitro; de dissolução de suspensões de sulfassalazina para uso em doenças inflamatórias crônicas intestinais. Desenvolveram-se três formulações baseadas em fornecedores diferentes de pó de sulfassalazina. A sulfassalazina foi caracterizada quanto a Teor, Infravermelho por Transformada de Fourier (FTIR), Calorimetria Diferencial de Varredura (DSC), Difração de Raios-X (XRD), distribuição de tamanho das partículas, índice de polidispersão e solubilidade. A suspensão foi desenvolvida e caracterizada quanto a pH, viscosidade, densidade, tamanho de partícula, volume de sedimentação, teor e estudo de dissolução. Os valores de pH determinados foram levemente ácidos. O método de preparo das suspensões reduziu o tamanho das partículas e tornou a distribuição de tamanho mais homogênea. Os estudos de dissolução mostraram que a suspensão de sulfassalazina tem problemas de solubilidade em meios de caráter ácido, entretanto, sofre dissolução rápida acima de 85% em meios neutros ou contendo 0,5% de tensoativos como Polissobato 80. Além disso, as suspensões de sulfassalazina foram classificadas como formulações de dissolução imediata porque a partir de 20 minutos sofrem dissolução em torno de 100%.;This paper reports the development, characterization and;in vitro;dissolution behavior of sulfasalazine suspensions for treatment of chronic intestinal inflammatory diseases. Three formulations were developed, from powdered sulfasalazine obtained from different suppliers. The sulfasalazine was characterized regarding concentration, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), particle size distribution, polydispersion and solubility. The suspensions were developed and characterized regarding pH, viscosity, density, particle size, sedimentation volume, concentration and dissolution. The pH values were slightly acidic. The method of preparing the suspensions reduced the particle sizes and made the size distribution more homogeneous. The dissolution studies showed that the sulfasalazine suspensions had low solubility in acidic media, but dissolve quickly, reaching levels of 85%, in neutral media or media containing 0.5% of surfactants such as polysorbate 80. Besides this, the sulfasalazine suspensions were classified as having immediate dissolution because they reached dissolution levels near 100% in 20 minutes

    Use of stabilized sewage sludge on a humusless soil: I - physical properties and revegetation

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    The application of treated and stabilized sewage sludge to soils has been shown to be a viable disposal alternative, since costs are low and cause no negative impacts, but contribute to the restoration of the original characteristics of some degraded soils. This experiment was carried out in Mogi Guaçu, State of São Paulo (Brazil) to evaluate the effect of doses (0, 20, 40, and 80 Mg ha-1) of an organic compost of sewage sludge and grass residues on the recovery of a humusless soil, in particular on the soil physical properties and revegetation with native species. It was found that doses of sewage sludge compost did not change the soil physical properties at the site under study and the plant height and diameter of the chosen reforestation species were not influenced by increasing doses of sewage sludge compost applied to humusless soil, regardless of the succession group.A disposição do lodo de esgoto, estabilizado e tratado, em solos tem se mostrado uma alternativa viável, uma vez que pode ser feita com baixo custo e sem provocar impactos negativos, contribuindo também para o restabelecimento das características originais de alguns solos que sofreram processos de degradação. Com o objetivo de avaliar o uso de dosagens (0, 20, 40 e 80 Mg ha-1) de um composto orgânico de lodo de esgoto e resíduos de roçagem na recuperação de um solo decapitado, pelo seu efeito nos atributos físicos do solo e revegetação com espécies nativas, realizou-se um experimento em Mogi-Guaçu - SP. Concluiu-se que as dosagens de lodo de esgoto compostado não modificaram os atributos físicos analisados no solo do local e que a altura e o diâmetro médio das plantas do reflorestamento escolhido não sofrem influência das dosagens crescentes de composto de lodo de esgoto no solo decapitado, independentemente do grupo sucessional.53554

    Improving the phototoxicity of the zinc phthalocyanine by encapsulation in nanoparticles: preparation, characterization and phototherapy studies

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    Nanoparticles are widely utilized to overcome drugs insolubility problems and sustain release improving the bioavailability. Zinc phthalocyanine, a hydrophobic photosensitizer with solubility problems, was loaded in PLA nanoparticles. Photosensitizer loaded in polymeric nanoparticles was produced with the following characteristics: size in the 200-300 nm range, negative zeta potential (-15 to -19 mV), low polydispersity index (2 ) or incubation time (2 to 4 h). The phototoxicity of the zinc phthalocyanine was improved by encapsulation in nanoparticles and this nanocarrier is a promising delivery system for photodynamic therapy use.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Could be FOXO3a, miR-96-5p and miR-182-5p useful for Brazilian women with luminal A and triple negative breast cancers prognosis and target therapy?

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    FOXO3a dysregulation is frequently implicated in tumorigenesis, and its inhibition can occur by several molecular mechanisms. Among these, post-transcriptional suppression by miRNAs has been associated with various cancers initiation. Here, we assessed the expression profiles of the most relevant miRNAs for breast tumorigenesis, using Luminal A (LA) and Triple-Negative (TN) breast cancer from Brazilian patients, by the quantitative real time-PCR method. Their potential prognostic role for the patients was also evaluated. We identified the miRNAs miR-96-5p and miR-182-5p, de-scribed as negative regulators of FOXO3A, with differential expression both in LA and TN tumors when compared to normal tissue. The miR-96-5p and miR-182-5p miRNAs were upregulated in LA (7.82 times, p < 0.005; 6.12 times, p < 0.005, respectively) and TN breast cancer samples (9.42 times, p < 0.0001; 8.51 times, p < 0.0001) compared to normal tissues. The samples with higher miR-96-5p and miR-182-5p expression (FR ≥ 4) were submitted for FOXO3a immunostaining. Reduced protein detection was observed in all of the tumors compared to normal tissues. The most prominent miRNA expression and FOXO3a protein suppression were observed in TN samples (p < 0.001), indicating the relevant role of these molecules in this tumor biology and clinical behavior. Our results corroborate the literature regarding to the relevance of FOXO3a in the breast cancer, and they open new perspectives for alternative target therapy options for Brazilian patients expressing both FOXO3a and its regulatory miRNAs
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