CELULOSE FIBROSA DO BAGACO DA CANA-DE-ACUCAR - AVALIACAO DA ACAO AGLUTINANTE/DESAGREGANTE EM COMPRIMIDOS CONTENDO FARMACO HIDROSSOLUVEL

In this work, a fibrous cellulose obtained from the sugar cane bagasse was analysed about its binder/disintegrating action and about its interference degree in the dissolution rate ('in vitro') of active principles, when incorporated in a compact system that has a water-soluble drug. It was used as reference drug the Lithium Carbonate, considering its solubility in water and it difficulties in the compressibility and flow rate. That cellulose was evaluated in a comparative study, involving another fibrous cellulose generally used in the tablet obtainment (Microcel 3E-200). After the experiment in methodologies of dry granulation and wet granulation, it was concluded that the analysed celluloses presents adequate binder/disintegrating efficience and they are equivalents in these aspect.

Avaliação do triticale (X triticosecale wittimack) para silagem

Silages from three cultivars of triticale (X Triticosecale wittimack) were evaluated at the UNESP, Jaboticabal, Brazil. The cultivars FCA VJ-CB-01, FCA VJ-CB-02, and FCA VJ-CB-03 were harvested for silage in three growing stages of maturity; beginning of flowering, (S1), milk stage (S2), and dough stages (S3). Data were analyzed by randomized complete block with three replications. The DM (%) values increased while the CP (%DM) and buffering capacity (me HCl/100 g DM) decreased with plant development. Silages of plants harvested at S3 stage had higher pH and N-NH3 values compared to the S1 and S2 silages. The soluble carbohydrates contents (%DM) were higher at the S2 stage (16.9%) and were not different at the S1 (8.7%) and S3 (9.2%) stages. The crude energy contents (Kcal/kg MS) increased while the ADF, NDF, cellulose, and hemicellulose (DM%) decreased due to the presence of dough grains. This was not observed with the lignin contents. The IVDMD values were 66.3, 60.1 and 58.9%, for plants harvested at the S1, S2, and S3 stages, respectively. The results showed that there was no difference among for chemical composition, crude energy, and for IVDMD.

Polybitoxins: A group of phospholipases A2 from the venom of the neotropical social wasp paulistinha (Polybia paulista)

The neotropical wasp Polybia paulista is very aggressive and endemic in south-east Brazil, where it frequently causes stinging accidents. By using gel filtration on Sephadex G-200, followed by ion-exchange chromatography on DEAE-Cellulose under a pH gradient, a group of four toxins (designated as polybitoxins-I, II, lII and IV) presenting phospholipase A2 (PLA2) activities was purified. These toxins are dimeric with mol. wts ranging from 115,000 to 132,000 and formed by different subunits. The four toxins contain very high sugar contents attached to their molecules (22-43% w/w) and presented different values of pH optimum from 7.8 to 9.0; when dissociated, only residual catalytic activities were maintained. The catalytic activities of polybitoxins (from 18 to 771 μmoles/mg per minute) are lower than that of PLA2 from Apis mellifera venom and hornetin from Vespa basalis. The polybitoxins presented a non-linear steady-state kinetic behavior for the hydrolysis of phosphatidylcholine at pH 7.9, compatible with the negative co- operativity phenomena. All of the polybitoxins were very potent direct hemolysins, especially the polybitoxins-III and IV, which are as potent as the lethal toxin from V. basalis and hornetin from Vespa flavitarsus, respectively; polybitoxin-IV presented hemolytic action 20 times higher than that of PLA2 from A. mellifera, 17 times higher than that of neutral PLA2 from Naja nigricolis and about 37 times higher than that of cardiotoxin from Naja naja atra venom.

Avaliacao preliminar da utilizacao do residuo industrial de man dioca (manihot esculenta granz) como excipiente em comprimidos: Caracteristicas fisicas e de compressao

The applicability of a residue of manioc (Manihot esculenta Granz) from industrial processing as a direct compression excipient was investigated in comparison with microcrystalline cellulose (Avicel® PH 101). Physical characteristics of the powders like bulk and tap densities, particle size, flow properties (flow rate, index of compressibility and angle of repose) and agglutination were evaluated. The residue had poor performance as excipient for direct compression. However, it showed better disintegration properties than Avicel. The possibility of its use as disintegrant agent will be confirmed on future studies.

Plant Cell Wall Research Related to Evolution and Chemical Defenses

The plant cell wall is composed mainly of polysaccharides some constituted of repeating units of a single sugar, as cellulose or by two or more sugars grouped in repeating oligosaccharide blocks as the galactomannans and xyloglucans. Variations in composition and fine structure of these cell wall polysaccharides have been used as taxonomic markers and in the comprehension of the evolutive process, particularly in the Leguminosae. Partial hydrolysis of these compounds give rise to oligomers, some of which are capable of eliciting the synthesis of defensive substances in plants named phytoalexins. Species which differ in respect to phytoalexin liberation also differ in cell wall composition, particularly in the pectic fraction of the wall. Pectinases (mainly endopolygalacturonases) present in fungi, have been shown to hydrolyze plant cell walls yielding phytoalexin-eliciting oligosaccharides which differ in composition and in eliciting capacity in different species. These differences can be associated with the capacity of a given species to produce phytoalexins. On the other hand, the phytoalexin induction in plants is being used as a method of producing novel bioactive secondary metabolites.

Polissacarídeos biodegradáveis úteis para a preparação de sistemas de liberação controlada de fármacos. Parte 1: Quitosana

Due to an increasing interest, a vast number of biodegradable polymers have been obtained recently. Polymers naturally produced, such as cellulose, starch, chitosan and alginate, represent biodegradable materials, with low toxicity and low cost. Among polysaccharides, chitosan has been of great interest of the industrial and academic research, due to its special qualities of biodegradability and biocompatibility and, on the other hand, to the versatility of its use in several physical forms and products. A significant growth in the development of new dosage forms capable to deliver the drug in a controlled and targeted way has been observed in these last years. Such pharmaceutical forms search, mainly, the reduction of the dose administered and of the administration frequency, the reduction of adverse side effects and, consequently, a better patient compliance. The present paper describes the use of chitosan in pharmaceutical products, especially in drug controlled delivery systems.

Purificação de lacases PPO-I de Botryosphaeria rhodina

Laccases are glycoprotein polyphenol oxidases which are involved in fungal pathogenicity and they are also useful for biotechnological applications. The ligninolytic ascomycete, Botryosphaeria rhodina, has been studied as producer of exopolysaccharide and PPO-I and PPO-II laccases induced by veratryl alcohol. However, as the induced laccases have not been isolated, the aim of this study was to purify the enzyme and to identify the carbohydrates constituents of the glycosidic moiety. The fungus was cultivated on broth Vogel, 1% glucose and 30.4mM veratryl alcohol during 4.5 days at 28°C/180 rpm. The extracellular fluid showed high carbohydrate concentration and the stability of PPO-I laccase under conditions of refrigeration and freezing at 4°C-18°C over 40 days. The purification was developed by ultrafiltration using a NMWL 100 and 30 kDa membrane, gelfiltration on Sephadex G-100, and ion-exchange chromatography on DEAE-cellulose. The purified laccase was identified as a glycoprotein, weight molecular 113 kDa, consisting of 40% protein and 60% carbohydrate identified by HPAEC-PAD as fucose, galactose, mannose, glucose and glucosamine.

Mineralización de la paja de caña de azúcar en suelo adicionado con viñaza (suproducto de la industria del alcohol de caña de azúcar) y fertilizante nitrogenado

Cellulose is the most abundant vegetable organic compound, being derived mainly from plant residues. The decomposition of sugar-cane (Saccharum officinarum L.) straw was studied in a period up to 90 days, through variables related to the carbon cycle, such as respiratory activity and CM-cellulase (CM, cellulose microcrystalline) and CMC-cellulase (CMC, carboxymethylcellulose) activities. The treatments consisted of 0, 0.5 and 1.0% of straw, in the presence and absence of vinasse (a sugar-cane alcohol industry byproduct) and nitrogen fertilizer. The respiratory and cellulase activities increased up to the 14th day of incubation and later decreased. The respiratory activity was 1.9 and 2.3 fold larger (P < 0.05) in the soil with 0.5 and 1.0% of straw added, respectively, in relation to the control. CM- and CMC- cellulase activities also increased from 1.8 to 2.9 and from 2.3 to 2.7 fold, respectively. The vinasse addition enhanced CO 2 production and CM-cellulase activity, however, no significant effect was observed on CMC-cellulase activity. The addition of N reduced both respiratory and cellulase activities. The decomposition of the sugar-cane straw may enhance soil nutrient cycling increasing agricultural production. © 2006 Instituto de Investigaciones Agropecuarias, INIA.

Utilization of different methodologies for the characterization of Hb Hasharon heterozygotes

Hb Hasharon has an electrophoretic mobility similar to that of Hb S in cellulose acetate and a mobility between Hb S and C at acid pH. In high-performance liquid chromatography, Hb Hasharon shows a distinct chromatographic profile and retention time. The origin of this variant is a mutation in codon 47 (GAC → CAC) of the α2-globin gene, resulting in the replacement of asparagine by histidine during the translation process. Ten blood samples from individuals suspected of being Hb Hasharon carriers were analyzed. In addition to classic laboratory tests and high-performance liquid chromatography, molecular analysis by polymerase chain reaction with restriction fragment length polymorphism designed in the laboratory was performed to confirm this mutation. The study of these cases showed that a combination of classical and molecular methodologies is necessary in the diagnosis of hemoglobinopathies for a correct hemoglobin mutant identification. The accurate identification of hemoglobin variants is essential for genetic counseling and choice of therapy. ©FUNPEC-RP.

Ethylcelullose microspheres containing sodium diclofenac: Development and characterization

The objective of the present study was the development and characterization of ethylcellulose microspheres containing diclofenac and the determination of the in vitro drug release profile. Microspheres were prepared by emulsification/solvent evaporation method using ethyl acetate as solvent for the polymer and water as non solvent. The microspheres were characterized by morphologic and granulometric analyses. The amount of encapsulated drug as well as its release profile in vitro were also determined. The product obtained was microparticles with smooth surface and narrow size distribution, about 50% of the particles being smaller than 5 μm. The methodology used allowed drug encapsulation with a good yield and the system provided a controlled release of diclofenac.

Desenvolvimentos da biopolpação no Brasil

Biopulping is a technology which application can be advantageous to mechanical or chemical pulping. It presents benefits such as the creation of stronger pulp, as well as energy or chemicals savings. This paper gives an overview of the recent efforts to develop biopulping processes in Brazil as well as provides critical information on biopulping development worldwide. Eucalyptus grandis wood chips have been biotreated by Ceriporiopsis subvermispora in a 50-ton biopulping pilot-plant and used to produce TMP and CTMP pulps on a mill scale, Up to 18% and 27% energy savings have been observed for producing 450-470 CSFreeness TMP and CTMP pulps. Despite darker bio-TMP pulps are produced, one-stage bleaching with 5% H2O2 was sufficient to improve brightness values to 70% and 72% for bio-TMP and control pulps, respectively. Understanding biopulping mechanisms is also relevant because more resistant and competitive fungal species could be selected with basis on a function-directed screen-ing project. As far as the chemical changes induced by the fungus in wood are concerned, recent efforts have pointed out for two different types of wood transformations. One of them involves intense lignin depolymerization in short biotreatment periods, while the other indicates that esterification reactions of oxalate secreted by the Jungas on the polysaccharides chains increase the water saturation point of the fibers. Both transformations are expected to affect the fiber-fiber bonding and, consequently, the physical resistance of wood.

Determinação de fármacos diuréticos em associação por cromatografia em camada delgada e espectrofotometria

A rapid, sensitive and reliable thin-layer chromatography/spectrophotometry screening procedure was developed for quantitative determination of diuretics associated in pharmaceutical dosage forms. The chromatographic method employed microcrystalline cellulose and butanol : acetic acid : water (4:1:1) or amilic alcohol : ammonium hydroxide 25% (9:1) as mobile phases and detection by U.V. light. The drugs were extracted using a simple procedure and were quantified by U.V. spectrophotometry. Results varied from 97.5 to 102.5% and are similar to those obtained by conventional methods. This method of quantification of diuretics is promising for quality control of drugs.

Influência das propriedades de granulados de celulose nas características físicas dos comprimidos

The compaction behavior of powdered solids can be strongly influenced by the physicochemical properties of excipients because they are frequently present in the tablet in larger amounts than the drug itself. The aim of this study was to assess the influence of the granule size of the cellulose on the physical characteristics of tablets produced in punches of different diameters, since this relation has never been explored in the literature. Granules of several sizes were produced by wet granulation and compressed in punches of various diameters by applying different forces. Size distribution, apparent density and flow of granules were assessed, as well as physical characteristics of the tablets (weight, hardness, friability and disintegration time). Reducing the granule size resulted in tablets of adequate crushing strength and fast disintegration; moreover, it allowed tablets to be produced without the need to use forces near the upper limit of the press, thus avoiding premature wear on the tabletting machine. Thus, once a suitable size for a given tablet formulation has been chosen, the granule size selected has been shown to determine the crushing strength of the tablet.