Cholesterol dissolution rate in micellar bile acid solutions: retarding effect of added lecithin.

In vitro studies on the dissolution rate of cholesterol monohydrate crystals in micellar bile acid solutions showed that the addition of lecithin decreases the dissolution rate even though lecithin increases the equilibrium solubility of cholesterol in these solutions. The reduction in rates caused by lecithin was attributed to a large crystal-solution interfacial barrier. An effective permeability coefficient for the interfacial barrier was calculated to be around 1.5 x 10(-5) centimeter per second for the transport of cholesterol molecules.