INTERACTIONS BETWEEN FOOD COMPONENTS AND DRUGS .3. INTERACTIONS BETWEEN PECTIN AND PROPRANOLOL

Bioavailability of drugs can be affected distinctly by interactions wi th food components. Effects of structural parameters of the soluble di etary fiber pectin on lipid-membrane transport of propranolol (1) was investigated in vitro using a two-compartment model with a dodecanol-c ollodium membrane at pH 7.2 and 37 degrees C. Starting from practicall y fully esterified citrus pectin two series of defined and in their st ructural parameters gradually varied pectins were prepared. In presenc e of pectins with a blockwise distribution of free COOH-groups the por tion of permeated 1 is significantly diminished with a decreasing degr ee of esterification (DE). On the other hand, only in the smallest DE pectins having statistically distributed free COOH-groups seemed to af fect the transport rate of 1. The viscosity of the tested pectins poss essed no significant influence on the passage of 1.