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1.
Braz. arch. biol. technol ; 64: e21200429, 2021. tab, graf
Article Dans Anglais | LILACS | ID: biblio-1345492

Résumé

Abstract The high consumption of antiaging cosmetics represents an outstanding opportunity for the development of new processes and attractive products in the cosmetic industry. Stability studies and sensory analyses are critical steps in the development process and production chain. Here we present a potential antiaging cosmetic product with innovative sensory characteristics. Caviar extract antioxidant properties were firstly evaluated by the DPPH method since it is an important mechanism against skin aging. Ca-alginate beads containing 2% of caviar extract and 0.2% of black pigment were prepared to obtain spheres similar to caviar. The beads were incorporated in a gel phase (hydroxyethylcellulose 2.5%) containing 3% of dimethylaminoethanol. Stability was evaluated in different storage conditions (sunlight exposure, 5 ± 2 °C, 37 ± 2 °C and r.t.) through the parameters: appearance, color and odor, pH (6-7), density (0.98-1.14 g.mL-1), centrifugation and average size. After approval by the Committee for Ethics in Research (n° 3.503.061), 30 volunteers tested the new formulation and answered a questionnaire. At 2%, caviar extract was able to scavenge 10.9% ± 0.58 of DPPH radical. Formulations showed good stability after 90 days, even considering the average size (7.47 ± 0.41 - 8.4 ± 0.65 mm2). 90% of the sensory test participants reported that they would buy the new product. Therefore, the new product developed demonstrates a promising potential as an attractive cosmetic product.


Sujets)
Cosmétiques , Alginates , Lotions de Beauté , Vieillissement de la peau/effets des médicaments et des substances chimiques
2.
Electron. j. biotechnol ; 25: 39-42, ene. 2017. tab, graf
Article Dans Anglais | LILACS | ID: biblio-1008418

Résumé

Background: Invert sugar is used greatly in food and pharmaceutical industries. This paper describes scaling-up batch conditions for sucrose inversion catalyzed by the recombinant Pichia pastoris BfrA4X whole cells expressing Thermotoga maritima invertase entrapped in calcium alginate beads. For the first time, we describe the application of a kinetic model to predict the fractional conversion expected during sucrose hydrolysis reaction in both, a model and a prototype bioreactor with 0.5- and 5-L working volume, respectively. Results: Different scaled-up criteria used to operate the 0.5-L bioreactor were analyzed to explore the invert sugar large scale production. After model inversion studies, a 5-L scaled-up reaction system was performed in a 7-L stirred reactor. Both scaled-up criteria, immobilized biocatalyst dosage and stirring speed, were analyzed in each type of bioreactors and the collected data were used to ensure an efficient scale-up of this biocatalyst. Conclusions: To date, there is not enough information to describe the large-scale production of invert sugar using different scaled-up criteria such as dose of immobilized biocatalyst and stirring speed effect on mass transfer. The present study results constitute a valuable tool to successfully carry out this type of high-scale operation for industrial purposes.


Sujets)
Pichia/métabolisme , Saccharose/métabolisme , Biotechnologie/méthodes , Pichia/cytologie , Saccharose/composition chimique , Cinétique , Bioréacteurs , Thermotoga maritima/enzymologie , Alginates , Enzymes immobilisées , Biocatalyse , Hydrolyse
3.
Article Dans Anglais | IMSEAR | ID: sea-177011

Résumé

Immobilization is a method used for the preservation of enzymes as this method provides enhanced resistance to the changes in certain environmental conditions like pH/temperature. The advantage of immobilization (IMB) of live bacterial cells is especially high due to their role in environmental monitoring due to their low cost, easy handling and high sensitivity to the environment. Through our project we tried to show that this method of IMB is effective in the preservation of microorganisms. We used natural dyes during the course of our project which were extracted from grinding of fruits and vegetables such as pomegranate, beetroot and carrot. We used Sodium Alginate beads so that there were a good number of beads formed that helped for the proper entrapment of microorganisms E. coli and bacillus for future use. Natural dyes were chosen over synthetic dyes due to their environmental friendliness, cost effectiveness and less complexity. To confirm if the method had been effective, we prepared a growth curve to check the growth of the microorganism and found out that this method could be used to store the microbes for a month’s duration.

4.
Article Dans Anglais | IMSEAR | ID: sea-159162

Résumé

The objective of the current study was to optimize the composition of alginate beads to produce ambroxol hydrochloride alginate beads with optimum specifications. The study employed beads based on sodium alginate solution (2% w/v) as the main component with calcium chloride solution as crosslinking agent as the prototype beads. The beads were prepared by syringe method. The effect of viscosity modifiers on the morphology, entrapment efficiency and drug release was studied. The prototype beads were spherical semitransparent with entrapment efficiency (EE) of 23%. Incorporation of polyvinylpyrrolidone (PVP) as a viscosity modifier produced spherical semitransparent beads with higher EE values compared with the prototype. Addition of carboxymethyl cellulose (CMC) produced oval opaque beads which have larger size and higher EE values compared with the prototype beads or those containing PVP only. Replacement of CMC with hydroxypropyl methyl cellulose (HPMC) produced semitransparent spherical beads with significant increase in the EE. Monitoring the drug release rate from different beads, the all the tested beads were able to retain the drug in the stomach condition. In the intestinal conditions the release rate depended on the composition of the beads with prototype beads librating most of its contents in the first 15 minutes. Formulations containing either CMC or HPMC were able to retard the drug release in the intestinal phase. In conclusion the study developed beads with optimum entrapment and release of ambroxol hydrochloride.

5.
Braz. j. pharm. sci ; 50(4): 741-748, Oct-Dec/2014. tab, graf
Article Dans Anglais | LILACS | ID: lil-741335

Résumé

Calcium alginate beads containing pomegranate peels' polyphenol extract were encapsulated by ionic gelation method. The effects of various formulation factors (sodium alginate concentration, calcium chloride concentration, calcium chloride exposure time, gelling bath time maintaining, and extract concentration) on the efficiency of extract loading were investigated. The formulation containing an extract of 1 g pomegranate peels in 100 mL distilled water encapsulated with 3 % of sodium alginate cured in 0.05 M calcium chloride for 20 minutes and kept in a gelling bath for 15 minutes was chosen as the best formula regarding the loading efficiency. These optimized conditions allowed the encapsulation of 43.90% of total extracted polyphenols and 46.34 % of total extracted proanthocyanidins. Microencapsulation of pomegranate peels' extract in calcium alginate beads is a promising technique for pharmaceutical and food supplementation with natural antioxidants.


Pérolas de alginato de cálcio, contendo polifenóis de extrato de casca de romã, foram encapsuladas pelo método de gelificação iônica. Os efeitos de vários fatores de formulação (concentração de alginato de sódio, concentração de cloreto de cálcio, cloreto de cálcio, o tempo de exposição, o tempo de manutenção do banho de gelificação e a concentração do extrato) sobre a eficiência de carga do extrato foram investigados. A formulação que contém 1 g extrato de casca de romã em 100 mL de água destilada, encapsulado com 3% de alginato de sódio curada em 0,05 M de cloreto de cálcio durante 20 minutos e mantido em banho de gelificação por 15 min foi escolhida como a melhor em relação à eficiência de carga. Estas condições otimizadas permitem o encapsulamento de 43,90% do total de polifenóis extraídos e de 46,34% do total de proantocianidinas extraídas. A microencapsulação de extrato de cascas de romã em esferas de alginato de cálcio é uma técnica promissora para a suplementação farmacêutica e de alimentos com antioxidantes naturais.


Sujets)
/analyse , Polyphénols , Préparation de médicament/méthodes , Antioxydants/analyse
6.
Braz. j. pharm. sci ; 49(4): 873-888, Oct.-Dec. 2013. ilus, tab
Article Dans Anglais | LILACS | ID: lil-704120

Résumé

The objective of this study was to formulate an oral sustained release delivery system of sodium diclofenac(DS) based on sodium alginate (SA) as a hydrophilic carrier in combination with chitosan (CH) and sodium carboxymethyl cellulose (SCMC) as drug release modifiers to overcome the drug-related adverse effects and to improve bioavailability. Microspheres of DS were prepared using an easy method of ionotropic gelation. The prepared beads were evaluated for mean particle size, entrapment efficiency, swelling capacity, erosion and in-vitro drug release. They were also subjected to various studies such as Fourier Transform Infra-Red Spectroscopy (FTIR) for drug polymer compatibility, Scanning Electron Microscopy for surface morphology, X-ray Powder Diffraction Analysis (XRD) and Differential Scanning Calorimetric Analysis (DSC) to determine the physical state of the drug in the beads. The addition of SCMC during the preparation of polymeric beads resulted in lower drug loading and prolonged release of the DS. The release profile of batches F5 and F6 showed a maximum drug release of 96.97 ± 0.356% after 8 h, in which drug polymer ratio was decreased. The microspheres of sodium diclofenac with the polymers were formulated successfully. Analysis of the release profiles showed that the data corresponds to the diffusion-controlled mechanism as suggested by Higuchi.


O objetivo deste estudo foi elaborar um sistema de entrega de oral de liberação sustentada de diclofenaco sódico (DS) com base em alginato de sódio (SA), como um transportador hidrofílico em combinação com quitosana (CH) e carboximetilcelulose de sódio (SCMC) como modificadores de liberação de fármaco para diminuir os efeitos adversos e melhorar a biodisponibilidade. Prepararam-se microesferas de DS usando um método fácil de geleificação ionotrópica. Avaliaram-se os grânulos preparados quanto ao tamanho médio de partícula, eficiência de compressão, inchaço in vitro, erosão e capacidade de liberação de fármacos. Estes tammbém foram submetidos a vários estudos, como espectrometria no infravermelho com transformada de Fourier (FTIR) para compatibilidade de fármaco e polímero, microscopia eletrônica de varredura para morfologia de superfície, análise de difração de raios-X (XRD) do pós e análise calorimétrica diferencial de varredura (DSC) para determinar o estado físico do fármaco nos grânulos. A adição de SCMC durante a preparação de grânulos do polímero resultou em fármacos com menor carga de fármaco e liberação prolongada do DS. O perfil de liberação dos lotes F5 e F6 apresentou máximo de fármaco liberado de 96,97±0,356% após 8 h após o que a proporção do fármaco no polímero foi diminuída. As microesferas de diclofenaco de sódio com os polímeros foram formuladas com sucesso. A análise dos perfis de liberação mostrou que os dados correspondem ao mecanismo de difusão controlada, como sugerido por Higuchi.


Sujets)
Diclofenac/analyse , Microsphères , Polymères/analyse , Alginates/analyse , Agents Gélifiants
7.
Article Dans Anglais | IMSEAR | ID: sea-150963

Résumé

The main objective of the present study was to prepare and evaluate the colon-specific pectin alginate microspheres of 5-fluorouracil (5-FU) for the treatment of colon cancer. Calcium alginate beads were prepared by extruding 5-FU loaded alginate solution to calcium chloride solution and gelled spheres were formed instantaneously by ionotropic gelation reaction using different ratios of 5- FU and alginate, alginate and calcium chloride, stirring speeds (500-1500 rpm) and reaction time. The core beads were coated with ethyl cellulose to prevent drug release in the stomach and provide controlled dissolution of enteric coat in the small intestine and maximum drug release in the colon. Morphology and surface characteristics of the formulation were determined by scanning electron microscopy. In vitro drug release studies were performed in conditions simulating stomach to colon transit in the presence and absence of pectinase enzyme. No significant release was observed at acidic pH, however, when it reached the intestinal pH where ethyl cellulose starts to dissolve, drug release was observed. Also, release of drug was found to be higher in presence of pectinase enzyme. The DSC and FT-IR studies were also indicates there were no interactions between the drug and the polymers used.

8.
Braz. j. pharm. sci ; 46(4): 785-793, Oct.-Dec. 2010. ilus, graf, tab
Article Dans Anglais | LILACS | ID: lil-622879

Résumé

The objective of this study was to develop a sustained release dosage form of Trimetazidine dihydrochloride (TMZ) using a natural polymeric carrier prepared in a completely aqueous environment. TMZ was entrapped in calcium alginate beads prepared with sodium alginate by the ionotropic gelation method using calcium chloride as a crosslinking agent. The drug was incorporated either into preformed calcium alginate gel beads (sequential method) or incorporated simultaneously during the gelation stage (simultaneous method). The beads were evaluated for particle size and surface morphology using optical microscopy and SEM, respectively. Beads produced by the sequential method had higher drug entrapment. Drug entrapment in the sequential method was higher with increased CaCl2 and polymer concentration but lower with increased drug concentration. In the simultaneous method, drug entrapment was higher when polymer and drug concentration were increased and also rose to a certain extent with increase in CaCl2 concentration, where further increase resulted in lower drug loading. FTIR studies revealed that there is no interaction between drug and CaCl2. XRD studies showed that the crystalline drug changed to an amorphous state after formulation. Release characteristics of the TMZ loaded calcium alginate beads were studied in enzyme-free simulated gastric and intestinal fluid.


O objetivo deste estudo foi desenvolver forma de liberação controlada de dicloridrato de trimetazidina (TMZ) utilizando transportador plomérico natural em ambiente completamente aquoso. A TMZ foi presa em pérolas de alginato de cálcio preparadas com alginato de sódio pelo método de gelatinização ionotrópica, usando cloreto de cálcio como agente de formação de ligações cruzadas. O fármaco foi incorporado nas pérolas de gel de alginato de cálcio (método sequencial) ou incorporado, simultaneamente, durante o estágio de gelificação (método simultâneo). As pérolas foram avaliadas quanto ao tamanho das partículas e morfologia da superfície utilizando microscopia óptica de SEM, respectivamente. As pérolas produzidas pelo método sequencial apresentaram maior capacidade de inclusão. No método sequencial, a inclusão de fármaco foi maior com o aumento de CaCl2 e da concentração do plímero, mas menor com o aumento da concentração de fármaco. No método simultâneo, a inclusão de fármaco foi mais alta quando as concentrações de fármaco e plímero foram aumentadas e, também, atingiram certa extensão com aumento na concentração de CaCl2, cujo aumento posterior resultou em carga menor de fármaco. Estudos de FTIR revelaram que não há interação entre fármaco e CaCl2. Estudos de XRD mostraram que o fármaco mudou do estado cristalino para o amorfo após a formulação. As características de liberação de TMZ das pérolas carregadas com alginato de cálcio foram estudadas em fluidos simulados, gástrico e intestinal, livres de enzima.


Sujets)
Calcium/pharmacologie , Capsules/analyse , Capsules/pharmacocinétique , Capsules/composition chimique , Techniques in vitro , Conception de médicament , Agents Gélifiants , Chimie pharmaceutique/méthodes , Sodium , Trimétazidine/pharmacologie
9.
Genet. mol. biol ; 31(1): 136-140, 2008. ilus, graf
Article Dans Anglais | LILACS | ID: lil-476163

Résumé

An alternative approach to somatic gene therapy is to deliver the therapeutic protein by implanting genetically modified cells that could overexpress the gene of interest. Microencapsulation devices were designed to protect cells from host rejection and prevent the foreign cells from spreading while allowing protein secretion. Alginate microcapsules form a semi-permeable structure that is suitable for in vivo injection. In this study, we report an effective laboratory protocol for producing calcium alginate microcapsules, following optimization of uniformly shaped and sized particles containing viable cells. Encapsulation of baby hamster kidney (BHK) cells in alginate microcapsules was performed using a simple device consisting of a cylinder of compressed air and a peristaltic pump. A cell suspension flow of 100 mL h-1 and an air jet flow of 10 L min-1 produced the best uniformity of microcapsule size and shape. Cells maintained viability in culture for 4 weeks without any signs of necrosis, and protein diffusion was observed during this period. Our results clearly demonstrated that microisolation of BHK cells in alginate using a simple assembly device could provide an environment that is capable of preserving live cells. In addition, encapsulated cells under the conditions described were able to secrete an active enzyme even after four weeks, thus becoming potentially compatible with therapeutic protein delivery.


Sujets)
Animaux , Rats , Alginates/composition chimique , Systèmes de délivrance de médicaments , Thérapie génétique , Techniques de culture cellulaire , Préparation de médicament
10.
Electron. j. biotechnol ; 10(2): 211-220, Apr. 15, 2007. graf, tab
Article Dans Anglais | LILACS | ID: lil-499180

Résumé

The exopolysaccharide (EPS)-producing cultures such as Lactobacillus rhamnosus RW-9595M present a challenge for the culture producers because the high viscosity of the fermented growth medium makes it difficult to recover the cells by centrifugation or filtration. This study examined four approaches to reduce viscosity of the medium while producing high cell densities: incubation temperature, extended incubation in the stationary growth phase, production in alginate gel beads and fed-batch fermentation technology. Automated spectrophotometry (AS) was used to study the effects of temperature, pH and lactate level on growth of the strain. In AS assays, there was no significant difference in final maximal biomass production at temperatures ranging between 34 ºC to 44 ºC, but lower yields were noted at 46 C. A pH below 6.0 and a lactate concentration higher than 4 percent almost completely prevented growth. Under batch fermentation conditions, the viscosity of the medium obtained at 37 C was two fold higher than for 44 ºC. For cultures produced at 37 ºC, centrifugation at 10000 g during 5 min did not allow complete recovery of cells, in contrast to cultures grown at 44 ºC. An extended period of incubation (5 hrs) in the stationary growth phase did not reduce the final viscosity of the growth medium. For similar biomass levels, the glucose-based fed-batch fermentation allowed a 40 percent reduction in viscosity of the fermented medium in comparison to traditional batch cultures. High-density cell populations (3 x 10(10) CFU/g) were obtained when L. rhamnosus RW-9595M was grown in alginate beads. However, overall biomass yields in the immobilized cell bioreactor were half of those obtained in free-cell fermentations. Therefore three methods of producing concentrated EPS-producing cultures are proposed.


Sujets)
Milieux de culture , Lacticaseibacillus rhamnosus/isolement et purification , Lacticaseibacillus rhamnosus/croissance et développement , Polyosides bactériens/isolement et purification , Polyosides bactériens/biosynthèse , Alginates , Techniques bactériologiques , Fermentation , Microbiologie alimentaire , Concentration en ions d'hydrogène , Lactobacillus/métabolisme , Lactose/analyse , Température , Viscosité
11.
Chinese Journal of Nosocomiology ; (24)2006.
Article Dans Chinois | WPRIM | ID: wpr-589049

Résumé

OBJECTIVE To establish a rat model of pulmonary infection by inoculating Pseudomonas aeruginosa to Sprague-Dawley(SD) rats and evaluate it.METHODS Two hundred SD rats were divided into 2 groups: the P.aeruginosa group and the control group,P.aeruginosa was embedded in minute seaweed alginate beads by an ejection set with an acuminate hole.Then the beads were inoculated into the rats′ lung through tracheal intubation.RESULTS The bacteriological values: P.aeruginosa was detected from rats of infected groups.Bacterial number was higher than 105CFU/g 3 and 7 days after infection and higher than 103CFU/g 14 and 28 days after infection.The pathological changes showed: 3 and 7 days after infection,lung abscess,edema,and consolidation could be seen from lungs of infected groups.At optical microscopy,alginateP.aeruginosa caused a pronounced inflammatory reaction with polymorphonuclear cells surrounding a bead.Fourteen and 28 days after infection,fibrinous adhesions and granulomas became the major pathological changes.CONCLUSIONS The animal model of pulmonary infection can be established by inoculating P.aeruginosa embedded in minute seaweed alginate beads made by an ejection set with an acuminate hole to SD rats.

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