A new approach to the granulation of beta-cyclodextrin inclusion complexes

Cyclodextrins (CDs) are annular oligosaccharides containing 6-12 glucose unities joined together by alpha-1,4 bonds. They have a conical-truncated shape with a lipophilic cavity in which different molecules can be included resulting in a stable inclusion complex. The cyclodextrins have been widely applied in pharmaceutical technology with the objective of increasing the solubility, stability and bioavailability of drugs in different pharmaceutical dosage forms, such as tablets. In order to obtain beta-CD tablets, liquid dispersions of drug/beta-CD are usually submitted to different drying processes, like spray-drying, freeze-drying or slow evaporation, being this dry material added to a number of excipients. However, such drying processes can generate particulate materials showing problems of flow and compressibility, needing their conversion into granulates by means of wetting with granulation liquid followed by additional drying. In this work, the main objective was to evaluate the preparation of tablets without the need of this additional drying step. For this purpose an aqueous dispersion containing acetaminophen/beta-CD complex and cornstarch was dried using a spouted bed and the obtained granules were compressed in tablets. Acetaminophen was used as model drug due to its low water solubility and the inexpensive and widely available cornstarch was chosen as excipient. Acetaminophen powder was added into a beta-cyclodextrin solution prepared in distilled water at 70 degrees C. Stirring was kept until this dispersion cooled to room temperature. Then cornstarch was added and the resulting dispersion was dried in spouted bed equipment. This material was compressed into tablets using an Erweka Korsh EKO tablet machine. This innovative approach allowed the tablets preparation process to be carried out with fewer steps and represents a technological reliable strategy to produce beta-cyclodextrin inclusion complexes tablets. (C) 2010 Elsevier By. All rights reserved.

Both alpha(1)- and beta(1)-adrenoceptors in the bed nucleus of the stria terminalis are involved in the expression of conditioned contextual fear

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

Bed nucleus of the stria terminalis alpha(1) and alpha(2) adrenoceptors differentially modulate the cardiovascular responses to exercise in rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hypothalamic supraoptic but not paraventricular nucleus is involved in cardiovascular responses to carbachol microinjected into the bed nucleus of stria terminalis of unanesthetized rats

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

Bed nucleus of the stria terminalis and the cardiovascular responses to chemoreflex activation

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

Use of platelet-rich plasma under autogenous onlay bone grafts

Objectives: To analyze the healing of autogenous onlay bone grafts in three different situations, focusing on the interface area.Material and methods: Sixteen rabbits underwent autogenous bone graft surgeries in the calvaria. The block bone grafts were positioned in three different situations: direct contact between bone graft and receptor bed, graft interposed by particulate bone, and graft interposed by platelet-rich plasma (PRP). After 7, 15, 30, and 60 days, the specimens were retrieved for histological and morphometric evaluation.Results: All groups healed uneventfully and presented incorporation of the grafts after 30 days. A slightly more evident new bone formation could be observed in the PRP group in the first analyzed period, and an earlier maturation of bone in the last period, although no statistically significant differences were achieved.Conclusion: the use of additional material between the bone graft and the receptor bed when using the onlay technique must be carefully considered, taking into account the size of the reconstruction and the cost/benefit relation. The addition of PRP in between autogenous bone blocks and the receptor bed did not confer significant benefit for the new bone formation and healing on the calvaria of bone of rabbits.

Influence of the ratio of particulate autogenous bone graft/platelet-rich plasma on bone healing in critical-size defects: a histologic and histometric study in rat calvaria

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

Influence of the proportion of particulate autogenous bone graft/platelet-rich plasma on bone healing in critical-size defects: An immunohistochemical analysis in rat calvaria

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

Retention of particulate organic matter in a tropical headstream

Retention of particulate organic matter was investigated over a range of water discharges in pool and riffle zones of a tropical stream (Itauna Stream, São Paulo, Brazil). A closed-system leaf release and capture method was used to quantify leaf retention in a 50-m reach of the stream. Instantaneous retention rates (k) were calculated by a negative exponentialmodel and specific retention rates (ke) computed for each 1m interval. The mean k was 0.0161 +/- 0.0101 (S.E.) and ranged from 0.005 to 0.036 during the study period. This suggests a low retention of particulate matter. The evidence provided by this study shows that there was a relationship between retention and discharge. At low discharges, greater percentages of leaves were retained in a 3-h period while high discharges resulted in low retention percentages within the studied reach. In the Itauna Stream, no significant difference (p < 0.05) was found between the ke values of pool and riffle zones.

Endoglucanase production with the newly isolated Myceliophtora sp. i-1d3b in a packed bed solid state fermentor

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

Biosorption and desorption of lanthanum(III) and neodymium(III) in fixed-bed columns with Sargassum sp.: Perspectives for separation of rare earth metals

Rare earth (RE) metals are essentials for the manufacturing of high-technology products. The separation of RE is complex and expensive; biosorption is an alternative to conventional processes. This work focuses on the biosorption of monocomponent and bicomponent solutions of lanthanum(III) and neodymium(III) in fixed-bed columns using Sargassum sp. biomass. The desorption of metals with HCl 0.10 mol L-1 from loaded biomass is also carried out with the objective of increasing the efficiency of metal separation. Simple models have been successfully used to model breakthrough curves (i.e., Thomas, Bohart-Adams, and Yoon-Nelson equations) for the biosorption of monocomponent solutions. From biosorption and desorption experiments in both monocomponent and bicomponent solutions, a slight selectivity of the biomass for Nd(III) over La(III) is observed. The experiments did not find an effective separation of the RE studied, but their results indicate a possible partition between the metals, which is the fundamental condition for separation perspectives. (C) 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012

Chemopreventive activity of compounds extracted from Casearia sylvestris (Salicaceae) Sw against DNA damage induced by particulate matter emitted by sugarcane burning near Araraquara, Brazil

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

Atmospheric particulate polycyclic aromatic hydrocarbons from road transport in southeast Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Burnt sugarcane harvesting: Particulate matter exposure and the effects on lung function, oxidative stress, and urinary 1-hydroxypyrene

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Start-up of horizontal anaerobic reactors with sludge blanket and fixed bed for wastewater treatment from coffee processing by wet method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)