Modulation of nonspecific binding in ultrafiltration protein binding studies.
Pharm Res
; 20(7): 1015-21, 2003 Jul.
Article
em En
| MEDLINE
| ID: mdl-12880287
ABSTRACT
PURPOSE:
The aim of this study was to reduce or prevent nonspecific binding (NSB) of compounds to ultrafiltration (UF) protein binding (PB) testing units.METHODS:
UF units (regenerated cellulose, MWCO 10K) were used for PB and NSB measurements with or without pretreatment with 5% tween 80 (TW 80) or 5% benzalkonium chloride (BAK) on the filter membrane. Dosing solutions (10 microM) in human serum and pH 7.4 phosphate-buffered saline were centrifuged at 3,000 g and room temperature after 1-h incubation in UF testing units. In parallel, a 96-well equilibrium dialyzer was used for PB and NSB measurements in equilibrium dialysis (ED) at 37 degrees C for 4 h. Samples of UF and ED were analyzed by LC/MS or LSC.RESULTS:
Severe NSB was observed for etoposide, hydrocortisone, propranolol, and vinblastine in UF. In contrast, TW 80 or BAK pre-treatment on the filter membrane decreased the NSB from 87-95% to 13-64% without causing a significant change in membrane integrity. When NSB was below 50% as a result of pretreating agents, PB data of marker compounds were comparable to those of ED.CONCLUSIONS:
The pretreated membrane with TW 80 or BAK showed significantly less NSB for compounds that had a tendency toward high membrane binding. A modified UF method with pretreatment improved the performance of UF and was able to produce comparable PB results to ED.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Preparações Farmacêuticas
/
Proteínas Sanguíneas
Limite:
Humans
Idioma:
En
Revista:
Pharm Res
Ano de publicação:
2003
Tipo de documento:
Article