Processo De Obtenção De Membranas De Quitosana Com Tamanhos De Poros Controlados

A presente patente de invenção trata de um processo de obtenção de membranas de quitosana com tamanho de poros controlável para uso em processos de separação, filtração, ultra filtração, cromatografia e como biomaterial. O processo desenvolvido compreende as seguintes etapas básicas: a) solubilização da quitosana (independe da massa molecular da quitosana) em solução de ácido acético; b) filtração desta solução; c) espalhamento desta solução em placas de vidro; d) secagem desta solução espalhada em vidro em estufas a temperaturas inferiores a 80°C; g) imersão das placas inteira ou parcialmente secas em solução de NaOH (que pode variar de 0,05 a 5,0M) até que a membrana se desprenda da placa de vidro sobre o qual se encontra.BR0204379 (A)B01D71/76B01D71/76BR20020204379B01D71/76B01D71/7

Production of chemically modified chitosan microspheres by a spraying and coagulation method

Chitosan microspheres can be used in several applications, as biomaterials, in biotechnology processes and as adsorbents. The control of particle size in microsphere production is important to make these applications viable. This study focuses on the production and morphological characterization of chitosan microspheres. Microspheres were prepared by a spraying and coagulation process. Particles underwent chemical modifications with glutaraldehyde, epichlorohydrin or acetic anhydride treatments. The microspheres presented a fairly good sphericity (0.74) but an irregular micro-surface morphology. The mean particle size (MPS) ranged from 140 to 281 mum and the mean standard deviation (MSD) from 119 to 238 mm. The conditions were modelled to provide desired MPS and MSD by using the response surface methodology (RSM).347352Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Simulated moving bed chromatography in the production of enantiomerically pure or enriched compounds in large scale

There is great interest nowadays in the use of preparative liquid chromatography as an effective tool for the production of enantiomerically pure, or enriched, compounds for the pharmaceutical industry. To make the chromatographic process economically attractive, attention is now focused on the choice of the chromatographic operating mode to minimize eluent consumption and to maximize productivity. Among the alternatives to the traditional batch chromatography, attention is now shifting towards simulated moving bed (SMB) technologies and a review covering the latest developments in this area seems timely. Several aspects of this important analytical technique are presented and details concerning the SMB technology for process optimization are outlined.10271037Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Processo De ObtenÇÃo Dos EnantiÔmeros De Verapamil Em Leito MÓvel Simulado Convencional E NÃo Convencional

PROCESSO DE OBTENÇÃO DOS ENANTIÔMEROS DE VARAPAMIL EM LEITO MÓVEL SIMULADO CONVENCIONAL E NÃO CONVENCIONAL. A presente invenção trata de um processo de obtenção de enantiômeros do fármaco verapamil por meio da cromatografia contínua em leito móvel simulado comvencional e não convencional. Se por um lado, os enantiômeros são atualmente separados apenas em escala analítico, em processo batelada, com visão estritamente farmcêutica, por outro lado a presente invenção permite o aumento de escala na produção dos enantiômeros do fármaco possibiltando agregar valor comercial ao produto e a realização de testes clínicos em pesquisas científicas do ramo com os enantiômeros separados. Além disso, a comercialização do fármaco, enantiomericamente puro, atenderá as exigências impostas por órgãos regulamentadores de saúde, no que diz respeito à caracterização dos perfis farmacocinético e farmacodinâmico de enantiômeros individuais. A presente invenção, utilizando-se duas técnicas distintas de leito móvel simulado, permite obter os enantiômeros com custo de operação baixo e produtividade desejável em escala de tempo relativamente curta quando comparada ao processo cromatográfico operado em regime batelada, empregado atualmente. Também permite reduzir o consumo de solvente e aumentar a recuperação dos enantiômeros por unidade de massa de fase estacionários quiral utilizada.BR102012019046 (A2)C07C255/40A61K31/277A61P9/12BR20121019046C07C255/40A61K31/277A61P9/1

Ascertainment of Surfactin Concentration in Bubbles and Foam Column Operated in Semi-Batch

This paper describes a mathematical model for the convection, diffusion, and balance phenomena for predicting the depletion curves, i.e., variations in the timed surface-active molecule concentration for fractionation processes in bubbles and foam column, operated in semi-batch. The model was applied for the purification of the surfactin solution and the results were compared with experimental data. Gibbs adsorption curves were obtained for the biosurfactant at different temperatures, and then adjusted with estimated parameters, according to the Langmuir adsorption model. The gas bubble sizes were optically determined. The isotherm adsorption parameters and bubble average diameter are crucial for the attainment of the depletion curves, generated by the model described. The results demonstrate that the process is most effective when operating a column with reduced gas flow and low initial concentration. A top product with two or thirty times greater concentration than the initial one was achieved and the highest biosurfactant concentrations were attained for higher operating temperatures. It was also observed that bubble diameter increased with a higher gas flow. The adjustment obtained for the adsorption curves of Gibbs was satisfactory. Therefore, there was evidence that surfactin molecules adsorb in monolayers in the liquid–gas interface

Separação cromatográfica quiral de anestésicos a partir de soluções diluídas e concentradas em escala preparativa Chiral chromatographic separation of anesthetics from dilute and concentrated solutions under preparative scale

<abstract language="eng">In this work the separation of the chiral anesthetic compounds ketamine and bupivacaine was development using two chiral stationary phases (CSP). Ketamine enantiomers were well separate in the polysaccharide-based CSP (microcrystalline cellulose triacetate - MCTA) while bupivacaine in the tartardiamide-based CSP (Kromasil CHI-TBB). In both cases, the effect of temperature was investigated under analytical conditions. An improvement in the separation performance with temperature was observed. Thermodynamic parameters were evaluated by the van't Hoff plot. We concluded that enthalpic effects controlled the retention in these chiral columns. The enantiomers of ketamine and bupivacaine were separated under overloaded conditions with a good performance

Continuous Chromatographic Separation Of A Baclofen Precursor (n-boc-4-[p-chloro-phenyl]-2-pyrrolidone) In A Simulated Moving Bed Using A Polysaccharide Carbamate As Chiral Stationary Phase.

Liquid chromatography is known as one of the most flexible, efficient and cost-effective methods to resolve racemic mixture in order to attend the growing demand of the pharmaceutical industry for pure enantiomeric compounds. Cellulose tris(3,5-dimethylphenylcarbamate) is frequently used as a stationary phase for enantiomeric separations because of its attractive properties, including high enantioselectivity, high loading capacity and good mechanical stability. In this study, we investigated the usefulness of cellulose tris(3,5-dimethylphenylcarbamate) as the stationary phase and of ethanol and hexane mixtures as the mobile phases for the chromatographic separation of potential pharmaceutical intermediates. Using adsorption equilibrium data, we determined the optimal operational conditions for the separation of the N-Boc-4-[p-chloro-phenyl]-2-pyrrolidone enantiomers - a baclofen precursor - in a semi-preparative scale simulated moving bed unit. This unit was used to obtain high purity enantiomers on a scale of 1g/day. The outlet streams were analyzed by an on-line system that consisted of a UV-vis spectrophotometric unit, a polarimeter, and HPLC. Enantiomeric purities of up to 97% were obtained for the raffinate stream and up to 90% for the extract stream.1119156-6