Interactions between food components and drugs. Part 3. Interactions between pectin and propranolol.

Bioavailability of drugs can be affected distinctly by interactions with food components. Effects of structural parameters of the soluble dietary fiber pectin on lipid-membrane transport of propranolol (1) was investigated in vitro using a two-compartment model with a dodecanol-collodium membrane at pH 7.2 and 37 degrees C. Starting from practically fully esterified citrus pectin two series of defined and in their structural parameters gradually varied pectins were prepared. In presence of pectins with a blockwise distribution of free COOH-groups the portion of permeated 1 is significantly diminished with a decreasing degree of esterification (DE). On the other hand, only in the smallest DE pectins having statistically distributed free COOH-groups seemed to affect the transport rate of 1. The viscosity of the tested pectins possessed no significant influence on the passage of 1.