Imipramine associations with plasma components and its uptake by cultured human cells

Role of plasma lipoproteins in modifying the biological activity of hydrophobic drugs

The plasma lipoprotein distribution of potential drug candidates is not commonly studied. For some hydrophobic drug candidates, attainment of similar plasma free drug levels has not been associated with uniform production of pharmacological activity in different animal species. It is well-known that plasma lipoprotein lipid profiles vary considerably between different animal species. In addition, human disease states can significantly influence plasma lipoprotein profiles, resulting in altered therapeutic outcomes. Current research has shown that lipoprotein binding of drug compounds can significantly influence not only the pharmacological and pharmacokinetic properties of the drug, but the relative toxicity as well. Elucidation of drug distribution among plasma lipoproteins is expected to yield valuable insight into factors governing the pharmacological activity and potential toxicity of the drug. This paper will present an historical perspective and summarize the latest research in the area of lipoprotein-drug interactions.

Plasma lipoproteins as drug carriers: pharmacological activity and disposition of the complex of beta-sitosteryl-beta-D-glucopyranoside with plasma lipoproteins

The ability of plasma lipoproteins to act as carriers in site-specific drug delivery systems was evaluated by determining the disposition and pharmacological effects of beta-sitosteryl-beta-D-glucopyranoside (SG, 3). In the disposition studies, [3H]SG was absorbed from the intestinal tract by the formation of chylomicrons and was specifically associated with lipoproteins in vivo. [3H]SG was incorporated into various rat plasma lipoproteins in vitro. [3H]SG complexed with the lower density lipoproteins (d less than 1.063 g/mL), especially with the intermediate density lipoproteins (1.006 less than or equal to d less than 1.019 g/mL) which following intravenous administration to rats. In pharmacological studies, the hemostatic effect of SG in mice and the inhibitory effect of SG on vascular permeability in rats were only observed after intravenous administration of the complexes of SG with the lower density lipoproteins. The same results were obtained after the intravenous administration of the complexes of SG with human and mouse lipoproteins.