38 research outputs found

    Characterizing the mechanism of quetiapine distribution in lipid-core nanocapsules pseudo-phases using a validated LC/UV method

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    Quetiapine is an atypical antipsychotic used to treat schizophrenia. However, despite great interest for its chronic therapeutic use, quetiapine has some important side effects such as weight gain induction. The development of a quetiapine nanocarrier can potentially target the drug into central nervous system, resulting in a reduction of systemic side effects and improved patient treatment. In the present work, a simple liquid chromatography/ultraviolet detection (LC/UV) analytical method was developed and validated for quantification of total quetiapine content in lipid core nanocapsules as well as for determination of incorporation efficiency. An algorithm proposed by Oliveira et al. (2012) was applied to characterize the distribution of quetiapine in the pseudo-phases of the nanocarrier, leading to a better understanding of the quetiapine nanoparticles produced. The analytical methodology developed was specific, linear in the range of 0.5 to 100 µg mL−1 (r2 > 0,99), and accurate and precise (R.S.D < ±5%). The absolute recovery of quetiapine from the nanoparticles was approximately 98% with an incorporation efficiency of approximately 96%. The results indicated that quetiapine was present in a type III distribution according to the algorithm, and was mainly located in the core of the nanoparticle because of its logD in the formulation pH (6.86 ± 0.4)

    Nanotecnologia e gravura em metal: o trabalho colaborativo no laboratório científico

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    This text is part of the postdoctoral research, developed in PPG in Pharmaceutical Sciences of UFRGS, in 2018, with funding from CNPq. The main goal of the research is to use nanotechnology knowledge to characterize, plan, develop and produce alternative non-toxic materials for use in the printmaking, such as varnishes and intaglio inks. We analyze the types, profile and size of particles present in the varnishes, to improve the alternative materials in order to obtain a differentiated technical and artistic response. We intend to offer new bases for the realization of the images made through the intaglio etching using new technologies from the production of new materials and also the comprehension (in nanoscales) of what we perceive intuitively through the graphic expression in the intaglio etching and printing lines, grooves, points and other incisions produced on the engraving plates.Este texto faz parte da pesquisa de pós-doutorado, desenvolvida no PPG em Ciências Farmacêuticas da UFRGS, em 2018, com financiamento do CNPq. O objetivo principal da pesquisa é utilizar os conhecimentos da área da nanotecnologia para caracterizar, planejar, desenvolver e produzir materiais alternativos não-tóxicos para uso na gravura, tais como vernizes de proteção e tintas de impressão. Analisamos os tipos e perfis de distribuição de tamanhos de partículas, que estão presentes nos vernizes, para aprimorar os materiais alternativos de modo a obter uma resposta técnica e artística diferenciada. Pretendemos oferecer novas bases para a realização das imagens realizadas através das gravuras com uso de novas tecnologias a partir da produção de novos materiais e também da compreensão (em nanoescala) daquilo que percebemos intuitivamente através da expressão gráfica nas gravações e impressões de linhas, ranhuras, pontos e demais incisões realizadas nas matrizes de metal

    CHARACTERIZING THE MECHANISM OF QUETIAPINE DISTRIBUTION IN LIPID-CORE NANOCAPSULES PSEUDO-PHASES USING A VALIDATED LC/UV METHOD

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    Quetiapine is an atypical antipsychotic used to treat schizophrenia. However, despite great interest for its chronic therapeutic use, quetiapine has some important side effects such as weight gain induction. The development of a quetiapine nanocarrier can potentially target the drug into central nervous system, resulting in a reduction of systemic side effects and improved patient treatment. In the present work, a simple liquid chromatography/ultraviolet detection (LC/UV) analytical method was developed and validated for quantification of total quetiapine content in lipid core nanocapsules as well as for determination of incorporation efficiency. An algorithm proposed b

    Nanoformulation shows cytotoxicity against glioblastoma cell lines and antiangiogenic activity in chicken chorioallantoic membrane

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    Glioblastoma (GB) is a histological and genetically heterogeneous brain tumor that is highly proliferative and vascularized. The prognosis is poor with currently available treatment. In this study, we evaluated the cytotoxicity and antiangiogenic activity of doxorubicin-loaded-chitosan-coated-arginylglycylaspartic acid-functionalized-poly(ε-caprolactone)-alpha bisabolol-LNC (AB-DOX-LNC-L-C-RGD). The nanoformulation was prepared by self-assembling followed by interfacial reactions, physicochemically characterized and evaluated in vitro against GB cell lines (U87MG and U138MG) and in vivo using the chicken chorioallantoic membrane assay (CAM). Spherical shape nanocapsules had a hydrodynamic mean diameter of 138 nm, zeta potential of +13.4 mV, doxorubicin encapsulation of 65%, and RGD conjugation of 92%. After 24 h of treatment (U87MG and U138MG), the median inhibition concentrations (IC50) were 520 and 490 nmol L−1 doxorubicin-equivalent concentrations, respectively. The treatment induced antiproliferative activity with S-phase cell-cycle arrest and apoptosis in the GB cells. Furthermore, after 48 h of exposure, evaluation of antiangiogenic activity (CAM) showed that the relative vessel growth following treatment with the nanocapsules was 5.4 times lower than that with the control treatment. The results support the therapeutic potential of the nanoformulation against GB and, thereby, pave the way for future preclinical studies

    Toltrazuril-loaded polymeric nanocapsules as a promising approach for the preventive control of coccidiosis in poultry

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    Coccidiosis is a disease caused by intracellular protozoan parasites of the genus Eimeria that affect the intestinal tract of poultry. However, strain resistance and drug residue in the carcass have drawn the attention of the productive sector. The nanotechnology can improve the biological effect of drugs, reducing of administered doses and toxic effects. Due to this, toltrazuril-load polymeric nanoparticles based on Eudragit® S100 (NCt) or poly-"-caprolactone (LNCt) were developed to prevent coccidiosis in broilers. Nanoformulations were produced and showed homogeneous particle diameter distribution in the nanometer range (z-average and D (4.3) 90%. Cell viability assays using avian fibroblasts showed that LNCt presented no relevant toxicity up to 72 h. LNCt was then prophylactically administrated to chicken followed by challenge with Eimeria oocysts. The evaluation of the small intestine and cecum showed that the treatment with LNCt (3.5 mg/kg/day) in drinking water reduced the lesion scores and oocysts excretion, similar to the reference medicine containing toltrazuril (Baycox®, 7 mg/kg/day). The current study shows the potential protective use of nanoencapsulating anticoccidial drugs as a promising approach for the control of coccidiosis in poultry

    Desenvolvimento tecnológico, estudo da fotoestabilidade e avaliação da permeação cutânea in vitro da benzofenona-3 a partir de nanocápsulas poliméricas incorporadas em diferentes veículos semi-sólidos

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    Nanocápsulas poliméricas têm sido propostas como carreadores para filtros solares com o objetivo de prolongar o tempo de resistência desses no estrato córneo. O presente trabalho teve por objetivo avaliar comparativamente a permeação cutânea in vitro da benzofenona-3 (BZ3) a partir de nanocápsulas poliméricas incorporadas em diferentes formulações semi-sólidas. Primeiramente, suspensões de nanocápsulas contendo concentrações crescentes de BZ3 foram preparadas, caracterizadas físico-quimicamente e sua estabilidade foi determinada. A suspensão contendo 5 mg/mL de BZ3 apresentou diâmetro médio de 247 ± 4 nm, potencial zeta de -9,50 ± 1,02 mV, pH de 6,6 ± 0,1, teor e taxa de associação próximos a 100 % e foi selecionada para a continuidade do estudo. Na segunda etapa do trabalho a suspensão de nanocápsulas contendo 5 mg/mL de BZ3 foi incorporada em diferentes formulações semi-sólidas, hidrogel (HGNCBZ3), creme-gel (CGNCBZ3) e emulsão água em silicone (SNCBZ3). Estas formulações semi-sólidas foram caracterizadas segundo teor, pH, diâmetro médio das nanocápsulas incorporadas e comportamento reológico. As formulações semi-sólidas apresentaram pH adequado para aplicação cutânea, teores experimentais próximos aos valores teóricos e comportamento reológico não-newtoniano pseudoplástico. A permeação cutânea do filtro solar foi avaliada através de células de difusão de Franz e as formulações contendo BZ3 nanoencapsulada apresentaram maior quantidade e tempo de resistência do filtro no estrato córneo, comparando com as formulações contendo o ativo livre. A SNCBZ3 apresentou maior quantidade da BZ3 no estrato córneo quando comparada ao HGNCBZ3 e ao CGNCBZ3. Em uma última etapa do trabalho avaliou-se a fotoestabilidade da BZ3 nanoencapsulada e livre frente à irradiação por UVA e concluiu-se que a nanoencapsulação aumenta a fotoestabilidade da BZ3. Também foi avaliada a alergenicidade do filtro solar químico e observou-se que, nem o filtro nanoencapsulado ou livre, nem as nanocápsulas sem o ativo, apresentaram sensibilização cutânea. Em conclusão, o conjunto dos resultados obtidos demonstra que estas formulações são sistemas promissores para a aplicação cutânea de filtros solares.Polymeric nanocapsules have been proposed as carriers for sunscreens in order to prolong the residence time of these substances in the stratum corneum. The aim of this work was to evaluate in vitro the skin permeation of benzophenone-3 (BZ3) from polymeric nanocapsules incorporated in different semi-solid formulations. Nanocapsule suspensions containing different concentrations of BZ3 were prepared, physico-chemically characterized and their stability was determinated. The suspension containing 5 mg/mL of the BZ3 presented average size of 247 ± 4 nm, zeta potential of - 9,50 ± 1,02 mV and pH values of 6,6 ± 0,1. This sample showed an amount of BZ3 and drug entrapment of 100 %. The nanocapsule suspension containing 5 mg/mL was incorporated in different semi-solid formulations, hydrogel (HGNCBZ3), cream-gel (CGNCBZ3) and emulsion water in silicon (SNCBZ3). The amount of BZ3, pH, average size and rheological properties of these formulations were evaluated. The formulations presented pH adequate for skin application and content of BZ3 close to 100 %. All semi-solid formulations showed pseudoplastic reological behavior. The skin permeation of BZ3 was evaluated by Franz diffusion cells and the formulation containing nanoencapsulated BZ3 showed an increase in the residence time of sunscreen in the stratum corneum and high amount of BZ3 compared to the formulations containing the free sunscreen. SNCBZ3 presented greater BZ3 quantity in the stratum corneum compared to HGNCBZ3 and CGNCBZ3. Finally, the photostability of free and nanoencapsulated BZ3 under UVA irradiation was evaluated and the results indicated that the nanoencapsulation increased the BZ3 photostability. The allergenicity of free and nanoencapsulated BZ3 was also determinated. Nanoencapsulated or free BZ3, and empty nanocapsules, did not present skin sensibilization. In conclusion, the results indicated that these formulations are promising delivery systems for the cutaneous applications of sunscreens

    Desenvolvimento tecnológico, estudo da fotoestabilidade e avaliação da permeação cutânea in vitro da benzofenona-3 a partir de nanocápsulas poliméricas incorporadas em diferentes veículos semi-sólidos

    Get PDF
    Nanocápsulas poliméricas têm sido propostas como carreadores para filtros solares com o objetivo de prolongar o tempo de resistência desses no estrato córneo. O presente trabalho teve por objetivo avaliar comparativamente a permeação cutânea in vitro da benzofenona-3 (BZ3) a partir de nanocápsulas poliméricas incorporadas em diferentes formulações semi-sólidas. Primeiramente, suspensões de nanocápsulas contendo concentrações crescentes de BZ3 foram preparadas, caracterizadas físico-quimicamente e sua estabilidade foi determinada. A suspensão contendo 5 mg/mL de BZ3 apresentou diâmetro médio de 247 ± 4 nm, potencial zeta de -9,50 ± 1,02 mV, pH de 6,6 ± 0,1, teor e taxa de associação próximos a 100 % e foi selecionada para a continuidade do estudo. Na segunda etapa do trabalho a suspensão de nanocápsulas contendo 5 mg/mL de BZ3 foi incorporada em diferentes formulações semi-sólidas, hidrogel (HGNCBZ3), creme-gel (CGNCBZ3) e emulsão água em silicone (SNCBZ3). Estas formulações semi-sólidas foram caracterizadas segundo teor, pH, diâmetro médio das nanocápsulas incorporadas e comportamento reológico. As formulações semi-sólidas apresentaram pH adequado para aplicação cutânea, teores experimentais próximos aos valores teóricos e comportamento reológico não-newtoniano pseudoplástico. A permeação cutânea do filtro solar foi avaliada através de células de difusão de Franz e as formulações contendo BZ3 nanoencapsulada apresentaram maior quantidade e tempo de resistência do filtro no estrato córneo, comparando com as formulações contendo o ativo livre. A SNCBZ3 apresentou maior quantidade da BZ3 no estrato córneo quando comparada ao HGNCBZ3 e ao CGNCBZ3. Em uma última etapa do trabalho avaliou-se a fotoestabilidade da BZ3 nanoencapsulada e livre frente à irradiação por UVA e concluiu-se que a nanoencapsulação aumenta a fotoestabilidade da BZ3. Também foi avaliada a alergenicidade do filtro solar químico e observou-se que, nem o filtro nanoencapsulado ou livre, nem as nanocápsulas sem o ativo, apresentaram sensibilização cutânea. Em conclusão, o conjunto dos resultados obtidos demonstra que estas formulações são sistemas promissores para a aplicação cutânea de filtros solares.Polymeric nanocapsules have been proposed as carriers for sunscreens in order to prolong the residence time of these substances in the stratum corneum. The aim of this work was to evaluate in vitro the skin permeation of benzophenone-3 (BZ3) from polymeric nanocapsules incorporated in different semi-solid formulations. Nanocapsule suspensions containing different concentrations of BZ3 were prepared, physico-chemically characterized and their stability was determinated. The suspension containing 5 mg/mL of the BZ3 presented average size of 247 ± 4 nm, zeta potential of - 9,50 ± 1,02 mV and pH values of 6,6 ± 0,1. This sample showed an amount of BZ3 and drug entrapment of 100 %. The nanocapsule suspension containing 5 mg/mL was incorporated in different semi-solid formulations, hydrogel (HGNCBZ3), cream-gel (CGNCBZ3) and emulsion water in silicon (SNCBZ3). The amount of BZ3, pH, average size and rheological properties of these formulations were evaluated. The formulations presented pH adequate for skin application and content of BZ3 close to 100 %. All semi-solid formulations showed pseudoplastic reological behavior. The skin permeation of BZ3 was evaluated by Franz diffusion cells and the formulation containing nanoencapsulated BZ3 showed an increase in the residence time of sunscreen in the stratum corneum and high amount of BZ3 compared to the formulations containing the free sunscreen. SNCBZ3 presented greater BZ3 quantity in the stratum corneum compared to HGNCBZ3 and CGNCBZ3. Finally, the photostability of free and nanoencapsulated BZ3 under UVA irradiation was evaluated and the results indicated that the nanoencapsulation increased the BZ3 photostability. The allergenicity of free and nanoencapsulated BZ3 was also determinated. Nanoencapsulated or free BZ3, and empty nanocapsules, did not present skin sensibilization. In conclusion, the results indicated that these formulations are promising delivery systems for the cutaneous applications of sunscreens
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