Thermal and Rheological Properties of a Family of Botryosphaerans Produced by Botryosphaeria rhodina MAMB-05

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermal behavior and stability of biodegradable spray-dried microparticles containing triamcinolone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermal characterization of solid lipid nanoparticles containing praziquantel

Solid lipid nanoparticles (SLNs), loaded and unloaded with praziquantel (PRZ-load SLN and PRZ-unload SLN) were prepared by two different procedures: (a) oil-in-water hot microemulsion method, obtaining at 70 degrees C an optically transparent blend composed of surfactant, co-surfactant, and water; and (b) oil-in-water microemulsion method, dissolving the lipid in an immiscible organic solvent, emulsified in water containing surfactants and co-surfactant, and then evaporated under reduced pressure at 50 degrees C. The mean diameter, polydispersity index (PdI), and zeta potential were 187 to 665 nm, 0.300 to 0.655, and -25 to -28 mV respectively, depending on the preparation method. The components, binary mixture, SLNs loaded and unloaded with PRZ, and physical mixture were evaluated by differential scanning calorimetry (DSC) and thermogravimetry (TG). The non-isothermal isoconversional Flynn-Wall-Ozawa method was used to determine the kinetic parameters associated with the thermal decomposition of the samples. The experimental data indicated a linear relationship between the apparent activation energy E and the pre-exponential factor A, also called the kinetic compensation effect (KCE), allowing us to determine the stability with respect to the preparation method. Loading with PRZ increased the thermal stability of the SLNs.

Nanoencapsulation and Characterization of Zidovudine on Poly(L-lactide) and Poly(L-lactide)-Poly(ethylene glycol)-Blend Nanoparticles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A discriminating dissolution method for glimepiride polymorphs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermal analysis of biodegradable microparticles containing ciprofloxacin hydrochloride obtained by spray drying technique

Thermal analysis has been extensively used to obtain information about drug-polymer interactions and to perform pre-formulation studies of pharmaceutical dosage forms. In this work, biodegradable microparticles of poly(D,L-lactide-co-glycolide) (PLGA) containing ciprofloxacin hydrochloride (CP) in various drug:polymer ratios were obtained by spray drying. The main purpose of this study was to investigate the effect of the spray drying process on the drug-polymer interactions and on the stability of microparticles using differential scanning calorimetry (DSC), thermogravimetry (TG) and derivative thermogravimetry (DTG) and infrared spectroscopy (IR). The results showed that the high levels of encapsulation efficiency were dependant on drug:polymer ratio. DSC and TG/DTG analyses showed that for physical mixtures of the microparticles components the thermal profiles were different from those signals obtained with the pure substances. Thermal analysis data disclosed that physical interaction between CP and PLGA in high temperatures had occurred. The DSC and TG profiles for drug-loaded microparticles were very similar to the physical mixtures of components and it was possible to characterize the thermal properties of microparticles according to drug content. These data indicated that the spray dryer technique does not affect the physicochemical properties of the microparticles. In addition, the results are in agreement with IR data analysis demonstrating that no significant chemical interaction occurs between CP and PLGA in both physical mixtures and microparticles. In conclusion, we have found that the spray drying procedure used in this work can be a secure methodology to produce CP-loaded microparticles. (C) 2007 Elsevier B.V. All rights reserved.

Thermo and photochromic properties of Na2O-WO3-SbPO4 glasses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermal stability and thermal decomposition of sucralose

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis, characterization and thermal studies on solid 3-methoxybenzoate of some bivalent transition metal ions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis, characterization and thermal behaviour on solid pyruvates of light trivalent lanthanides

Foram sintetizados compostos Ln-L no estado sólido, onde Ln significa os lantanídeos leves trivalentes e L é o piruvato. Estes compostos foram caracterizados e estudados utilizando-se a Termogravimetria e Termogravimetria derivada (TG/DTG), calorimetria exploratória diferencial (DSC) difratometria de raios X pelo método do pó, espectroscopia na região do infravermelho, análise elementar e complexometria. Os resultados permitiram obter informações com respeito a composição, desidratação, sitio de coordenação, comportamento térmico e a decomposição térmica destes compotos.

Synthesis, characterization and thermal behaviour of solid-state compounds of benzoates with some bivalent transition metal ions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis, characterization and thermal behaviour of solid-state compounds of 4-methoxybenzoate with lanthanum (III) and trivalent lighter lanthanides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermal studies on solid 1,4-bis(3-carboxy-3-oxo-prop-1-enyl) benzene of lighter trivalent lanthanides

Solid-state compounds of general formula Ln(2)L(3)center dot nH(2)O, where L represents 1,4-bis(3-carboxy-3-oxo-prop-1-enyl)benzene and Ln = La, Ce, Pr, Nd, Sm, were synthesized. Complexometric titrations with EDTA, thermogravimetry (TG), differential thermal analysis (DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, elemental analysis and infrared spectroscopy have been employed to characterize and to study the thermal behavior of these compounds in dynamic air atmosphere. The results led to information about the composition, dehydration, crystallinity, and thermal decomposition of the synthesized compounds.

Thermal and spectroscopic studies on solid Ketoprofen of lighter trivalent lanthanides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural and morphological characteristics of (Pb1-x Sr (x) )TiO3 powders obtained by polymeric precursor method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)