Caracterização e estabilidade físico-química de sistemas poliméricos nanoparticulados para administração de fármacos

Schaffazick, Scheila Rezende; Guterres, Sílvia Stanisçuaski; Freitas, Liane Lucy de Lucca; Pohlmann, Adriana Raffin

doi:10.1590/s0100-40422003000500017

Cited by 403 publications

(407 citation statements)

References 85 publications

(249 reference statements)

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“…15 The release of a drug from polymeric microparticles occurs through different mechanisms: desorption of the drug from the surface of the particles; diffusion of the drug through the pores of the polymeric matrix; erosion of the polymeric matrix; polymer degradation or a combination of different processes. 5,19 As PHB is very slowly degraded, the release profile of a drug from a PHB matrix is generally dependent on drug diffusion rather than on polymer degradation. 20 The results for the PHB molecular weight, pore size distributions and the morphology of the microparticles after the release assay indicated that the release of PXC from PHB microparticles occurs mainly through the two mechanisms: desorption of the drug from the surface of the particles and diffusion of the drug through the pores of the polymeric matrix.…”

Section: Discussionmentioning

confidence: 99%

Effect of preparation conditions on morphology, drug content and release profiles of poly(hydroxybutyrate) microparticles containing piroxicam

Bazzo¹,

Lemos‐Senna²,

Gonçalves³

et al. 2008

J. Braz. Chem. Soc.

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No presente estudo foram preparadas micropartículas de poli(hidroxibutirato) contendo piroxicam pela técnica de emulsão-evaporação do solvente. A influência de alguns parâmetros do processo sobre a eficiência de encapsulação do fármaco foi avaliada por meio de um planejamento fatorial do tipo 2 3 . A eficiência de encapsulação do piroxicam variou de 5,5 a 89,8%. Micropartículas ocas e irregulares, contendo cristais de fármaco na superfície, foram obtidas quando se utilizou 5 mL de clorofórmio como fase interna da emulsão. Com o ensaio de liberação in vitro evidenciouse que, após 8 h, todo o fármaco havia sido liberado para o meio. Micropartículas esféricas com superfície externa rugosa e porosa foram obtidas quando se utilizou 20 mL de diclorometano como fase interna e adicionou-se isopropanol à fase externa da emulsão. Essas microesferas foram capazes de controlar a liberação do piroxicam durante 50 h. Os resultados obtidos demonstraram que é possível obter micropartículas com características específicas pela otimização das condições empregadas no processo de encapsulação.In this study, poly(hydroxybutyrate) microparticles containing piroxicam were prepared by the oil-in-water emulsion-solvent evaporation method. The effects of some process conditions on drug content were determined using a 2 3 factorial design. The piroxicam loading efficiency varied from 5.5 to 89.8 %. Hollow and irregular microparticles with drug crystals on their surfaces were obtained when 5 mL of chloroform was used as the internal phase. In the release study, all of the piroxicam was released to the dissolution medium (phosphate buffer pH 7.4) after 8 h. Small spherical microspheres with a rough and porous polymeric matrix were obtained when 20 mL of dichloromethane was used as the internal phase and isopropanol was added to the external aqueous phase. These microspheres controlled the piroxicam release for approximately 50 h. The results demonstrated that it is possible to obtain microparticles with specific characteristics by the optimization of the process conditions.

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Section: Discussionmentioning

confidence: 99%

Effect of preparation conditions on morphology, drug content and release profiles of poly(hydroxybutyrate) microparticles containing piroxicam

Bazzo¹,

Lemos‐Senna²,

Gonçalves³

et al. 2008

J. Braz. Chem. Soc.

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“…This electric potential is influenced by changes in the particle interface with the dispersing medium, due to the dissociation of functional surface groups or the adsorption of ionic species present in the aqueous dispersion (Schaffazick, Guterres, 2003). The cellulose derivatives polymers, HPMC and EC, are non ionic materials and the CS is a positive polysaccharide due to the amino groups, which acquire electrical charge.…”

Section: Physicochemical Characterization Of Floating Microparticlesmentioning

confidence: 99%

Floating ability and drug release evaluation of gastroretentive microparticles system containing metronidazole obtained by spray drying

Nohemann

Almeida

Ferrari

2017

Braz. J. Pharm. Sci.

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Gastroretentive floating microparticles were developed and evaluated for the controlled metronidazole delivery for treatment of gastric disease. Floating microparticles, varying in proportions of chitosan and hydroxypropyl methylcellulose or ethylcellulose, were obtained by spray drying. Floating microparticles were characterized by physicochemical and in vitro studies, according to their floating ability and drug delivery. Microparticles presented mean diameter from 1.05 to 2.20 µm. The infrared spectroscopy confirmed the drug encapsulation and showed no chemical linkage between microparticles components. X-ray diffraction showed changes in the drug`s solid state, from crystalline to amorphous, indicating partial drug encapsulation, due to the presence of some crystalline peaks of metronidazole in microparticles. All microparticles floated immediately in contact of simulated gastric fluid and both floating and drug release profiles were dependent of microparticles composition. Microparticles samples constituted by chitosan and hydroxypropyl methylcellulose revealed the best relationship between floating duration and drug release, remaining floating during the occurrence of the drug release, ideal condition for the floating gastroretentive systems.Uniterms: Floating microparticle. Chitosan. Ethylcellulose. Hydroxypropyl methylcellulose. Controlled drug delivery.

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“…7 Os fármacos podem ser encapsulados por diferentes mecanismos, que incluem solubilização ou retenção na nanopartícula, conjugação ou adsorção. 8 Em uma situação ideal as nanopartículas, atuando como nanocarreadores, são capazes de transportar o fármaco para um local de destino específico (receptor, sítio ativo) para exercer a sua atividade terapêutica com o máximo de segurança. Os principais nanocarreadores engenheirados aplicados na terapêutica são: os lipossomas, as nanopartículas lipídicas, as micelas e as nanopartículas poliméricas.…”

Section: Tipos De Nanocarreadores Biodegradáveisunclassified

Impactos da nanotecnologia na saúde: produção de medicamentos

Dimer¹,

Friedrich²,

Beck³

et al. 2013

Quím. Nova

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Recebido em 4/7/13; aceito em 14/10/13; publicado na web em 24/10/13 IMPACT OF NANOTECHNOLOGY ON PUBLIC HEALTH: PRODUCTION OF MEDICINES. Several studies have described the benefits of nanoscience and nanotechnology (N&N) in different sectors such as agriculture, energy, environmental preservation, and public health. The rapid evolution of N&N can be shown through a panoramic analysis of scientific papers and patents. In the area of public health, it is estimated that the global market for nanotechnology products will expand to 160 billion U.S. dollars in 2015. The Brazilian government has also strengthened its innovative potential in N&N through economic subsidies, as observed for other countries. This review is focused on the current landscape of N&N in a therapeutic context, highlighting the development of nanotechproducts produced with biocompatible and biodegradable materials that are already commercially available or under investigation. Most studies under investigation are focused on the development of nanotechnology-based formulations intended for treatment of cancer, inflammatory, cardiovascular, and neurological diseases. Although there are several advantages of N&N in healthcare, many challenges have to be conquered to increase the availability of nanotechnology products in toxicological, preclinical and clinical studies, scale-up, regulatory, and private investments.Keywords: pharmaceutical nanotechnology; nanomedicine; drug. INTRODUÇÃOO crescente interesse em pesquisas relacionadas à nanociência e nanotecnologia (N&N) torna esta área um novo patamar do conhecimento, com imensos impactos científicos e econômicos. 1 Cabe salientar que políticas de Ciência e Tecnologia, C&T, estão sendo continuamente refletidas e discutidas gerando novas propostas de ações com o objetivo de superar desafios globais apresentados em escala municipal, estadual, regional e/ou nacional. Dentre os temas centrais destas políticas, destacam-se os relacionados à saúde, incluindo o desenvolvimento de fármacos e medicamentos, e matérias-primas e materiais "inovadores e tradicionais", abrangendo a ciência de nanomateriais. 2 Dados relacionados aos investimentos em N&N mostram que países como os EUA, Japão e os da Comunidade Europeia lideram financiamentos para o desenvolvimento desse setor, aumentando a competitividade de suas empresas. Estima-se que o mercado mundial de produtos para a saúde de base nanotecnológica crescerá até 160 bilhões de dólares em 2015. 3 Apesar de financiamentos mais modestos, vários países em desenvolvimento como o Brasil também investem no grande potencial da N&N e, em decorrência disso, têm apoiado iniciativas nacionais para a promoção dessa área, que poderão se traduzir em melhorias na qualidade de vida de suas populações. Enquanto a nanociência corresponde ao estudo dos fenômenos naturais que regem o comportamento de átomos, moléculas e estruturas na escala nanométrica, a nanotecnologia consiste na aplicação da nanociência para o controle e manipulação da matéria estruturada no nível atômico e molecula...

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Caracterização e estabilidade físico-química de sistemas poliméricos nanoparticulados para administração de fármacos

Cited by 403 publications

References 85 publications

Effect of preparation conditions on morphology, drug content and release profiles of poly(hydroxybutyrate) microparticles containing piroxicam

Effect of preparation conditions on morphology, drug content and release profiles of poly(hydroxybutyrate) microparticles containing piroxicam

Floating ability and drug release evaluation of gastroretentive microparticles system containing metronidazole obtained by spray drying

Impactos da nanotecnologia na saúde: produção de medicamentos

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