Despirogenação de soro antiofidico : adsorção seletiva em membrana de quitosana

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Contamination of therapeutic solutions by endotoxins (ET s) are ofmajor concem in the pharmaceutical industry. The ET s are lipopolyscaccharides found in the outer cell membranes of Gram-negative bacteria and are known to cause strong reactions in man after intravenous application. For this reason, the removal of ET s ftom therapeutic solutions is a major challenge in downstream processing. In this work, we studied the removal of ET s ftom snake antivenom serum, the therapeutic employed on the treatment of snake bite accidents. The technique studied for the this removal was the membrane filtration using cross-linked chitosan membranes. We investigated the chitosan membrane synthesis that presented appropriated features of flowrate, resistance to stress and adsorption area (13 rnL.min-l, 0,81 MPa and 15,9 cm2, respectively). The adsorption of proteins (antibodies) and ET s on the membrane was also investigated. The influence of three different buffer systems (Tris-HCI, sodium acetate and phosphate) on the adsorption of antibodies was studied. The best conditions found (lower antibody adsorption) were: pH 5,0 using acetate buffer, and pH 7,0 using Tris-HCI buffer (4,25% and 4,67% of antibody adsorption, respectively). The adsorption of ET s on the membrane when using the selected conditions was studied. Higher ET clearances were obtained using the Tris-HCI pH 7,0 buffer (97,7% and 99,0% for solutions containing initial ET concentrations of 150 and 1000 EU.rnL espectively). The membrane proved to be efficient on the removal of ET s ftom dilute snake antivenom serum (1,0 mg.mL-1of antibody concentration). ET removal efficiencies as high as 99,0% and antibody recovery of94,6% were obtained, for a solution containing an initial ET concentration of 1000 EU/rnL. The depyrogenation efficiency of high antibody concentration serum (approximately 15 mg.rnL-1) was also significant. The ET clearance and antibody recovery of a solution containing an initial ET concentration of 1000 EU.mL-1 were 98,7% and 82,0%, respectively. Moreover, the results indicated that antibody presence in the serum solutions was not a major obstacle for the ET removal processo. However, the antibody recoveries ftom these high concentrated serums were significantly reduced

ASSUNTO(S)

endotoxina membranas (tecnologia) adsorção quitosana

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