Effects of a Perfluorochenical Emulsion on Propranolol Binding by Alpha-I-Acid Glycoprotein

Abstract

AbstractThe binding of propranolol by a perfluorochemical emulsion (PFCE), cXiacid glycoprotein (AGP), and their mixtures was examined by a dialysis exchange method at 37°C. A sedimentation method was used to verify propranolol binding by the PFCE. Binding of 100 and 500 ng/ml drug by 100, 75, 50 and 25% v/v concentrations of the PFCE or of 0.067% AGP was determined. Propranolol was highly bound by the PFCE with a percent free propranolol in undiluted PFCE of 13.1% at both 100 and 500 ng/ml propranolol. Propranolol was moderately bound by AGP. The percent free propranolol in 0.067% AGP was 31.4% and 32.4% for 100 and 500 ng/ml propranolol, respectively. The percent bound propranolol was not significantly different when the emulsion was diluted to 75 and 50% v/v with 0.067% AGP solution rather than buffer. When the PFCE was further diluted to 25% v/v with the 0.067% AGP solution the percent free propranolol was significantly lower than in the 25% v/v PFCE alone or 75% v/v protein solution alone. Thus, the PFCE has a relatively large affinity and capacity for propranolol. Propranolol did not partition from buffer to the PFC liquid. This indicates that propranolol bound by the PFCE is associated only with the emulsifiers.