Tris lipidation--a novel drug delivery system that alters biodistribution.

Tris-lipidation uses Tris to produce drug-fatty acyl conjugates. Radiolabelled Tris-fatty acyl conjugates of methotrexate (MTX) were examined in biodistribution studies in BALB/c mice. Following delivery via a variety of routes, the Tris-lipidated compounds demonstrated features in common with other colloid drug delivery systems. Tissues of the reticuloendothelial system localised the drug following intravenous administration, and the compounds showed prolongation at the site of injection into muscle or fatty tissue, subcutaneously or when inhaled. These findings indicate that the Tris-lipidation platform could be classed as an alternative colloid drug delivery system.