RESUMO
We have recently described the incorporation of genistein into topical nanoemulsions. This study describes the physicochemical properties and the genistein permeation profile from these nanoemulsions. Formulations composed of egg lecithin, medium chain triglycerides (MCT) or octyldodecanol (ODD) and water were prepared by spontaneous emulsification. Irrespective of the oil core employed (MCT or ODD), this procedure yielded monodisperse emulsions with mean droplet sizes in the range of 230-280 nm. The addition of genistein in the oil phase, before emulsification, did not alter the properties of nanoemulsions. The amount of genistein incorporated in both formulations was close to 100% (1 mg/mL). Solubility and DSC experiments suggested that egg-lecithin may play an important role on the incorporation of genistein in nanoemulsions. Genistein permeation from formulations was assessed using pig ear skin in Franz type diffusion cells. The overall results showed a slow permeation profile for genistein from both nanoemulsions.Such results open interesting perspectives for the topical administration of genistein.
Assuntos
Genisteína/administração & dosagem , Nanopartículas/química , Administração Tópica , Animais , Varredura Diferencial de Calorimetria , Cultura em Câmaras de Difusão , Eletroquímica , Emulsões , Genisteína/química , Técnicas In Vitro , Indicadores e Reagentes , Microscopia Eletrônica de Transmissão , Óleos , Absorção Cutânea , Solubilidade , SuínosRESUMO
Thalidomide presents polymorphism and is a problematic drug due to its poor solubility and difficult tablet processability, which is the dosage form available in Brazil. In most cases, the pharmacopoeias specify do not address solid state characterization of drugs precisely. In this work, different thalidomide commercial samples were characterized by infrared spectroscopy, particle size analysis, scanning electron microscopy, and X-ray diffraction. In addition, the polymorphic forms were quantified for Rietveld analysis and their intrinsic dissolution rates were evaluated. The results demonstrated the market availability of different raw materials which lack of homogeneity due to differences related to crystalline constitution, crystal habit and intrinsic dissolution rate.
Assuntos
Talidomida/química , Avaliação Pré-Clínica de Medicamentos/métodos , Tamanho da Partícula , Solubilidade , Talidomida/análise , Difração de Raios X/métodosRESUMO
The aim of this study was to develop and validate an isocratic LC method for the quantification of genistein in topical nanoemulsions. The analyses were performed at room temperature on a reversed-phase C18 column using a mobile phase composed of methanol/water/acetonitrile (70:25:5, w/w/w) at 1.0 ml x min(-1). The detection was carried out on a UV detector at 327 nm. The linearity, in the range of 25-75 microg/ml, presented a determination coefficient (r2) higher than 0.999, calculated by the least square method. No interferences from the excipients (egg-lecithin, octyldodecanol or medium chain triglycerides) were detected. The R.S.D. values for intra- and inter-day precision experiments were lower than 2.3%. The recovery of genistein from nanoemulsions ranged from 96.6% to 106.6%. The excellent performance of the method, its linearity, accuracy and precision, demonstrate that it can be readily used to quantify genistein incorporated in nanoemulsions.
Assuntos
Anticarcinógenos/administração & dosagem , Anticarcinógenos/análise , Genisteína/administração & dosagem , Genisteína/análise , Administração Tópica , Fenômenos Químicos , Físico-Química , Cromatografia Líquida , Emulsões , Excipientes , Tamanho da Partícula , Reprodutibilidade dos TestesRESUMO
Solid dispersions containing carbamazepine (CBZ) associated with beta-cyclodextrin (betaCD) and/or hydroxypropyl methylcellulose were prepared by two different methods, spray-drying or physical mixture, and characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), infrared (IR) spectroscopy, and x-ray powder diffraction analysis (XRPD) studies. Scanning electron microscopy pictures showed that spray-drying produced a mixture of hollow, spherical, and partially shrunken microparticles of homogeneous materials, whereas the physical mixtures yielded heterogeneous systems in which all individual components could be identified. Thermal and IR analyses suggest the existence of a strong interaction between CBZ and excipients in spray-dried solid dispersions, but no CBZ polymorphic transition was detected by either IR spectroscopy or XRPD analysis after the spray-drying process.
Assuntos
Anticonvulsivantes/química , Carbamazepina/química , Ciclodextrinas/química , Metilcelulose/análogos & derivados , Metilcelulose/química , beta-Ciclodextrinas , Anticonvulsivantes/administração & dosagem , Varredura Diferencial de Calorimetria , Carbamazepina/administração & dosagem , Química Farmacêutica , Formas de Dosagem , Composição de Medicamentos , Excipientes/química , Derivados da Hipromelose , Microscopia Eletrônica de Varredura , Espectrofotometria Infravermelho , Tecnologia Farmacêutica , Difração de Raios XRESUMO
Se presenta una revisión sobre hipertensión arterial en diabetes mellitus, abordando aspectos tales como su prevalencia, situación fisiopatológica, efectos colaterales de la medicación antihipertensiva, la individualización y generalización del tratamiento y la hipertensión arterial en la nefropatía diabética. Se acompaña una guía de aplicación terapéutica
Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , HipertensãoRESUMO
Se presenta una revisión sobre hipertensión arterial en diabetes mellitus, abordando aspectos tales como su prevalencia, situación fisiopatológica, efectos colaterales de la medicación antihipertensiva, la individualización y generalización del tratamiento y la hipertensión arterial en la nefropatía diabética. Se acompaña una guía de aplicación terapéutica (AU)