Abstract:

A major cause of cardiovascular disease is high cholesterol (CH) levels in the blood, a potential soln. to which is the intake of phytosterols (PS) known as CH-reducing agents. One mechanism proposed for PS activity is the mutual cocrystn. of CH and PS from dietary mixed micelles (DMM), a process that removes excess CH from the transporting micelles. In this study, microemulsions (MEs) were used both as a model system for cocrystn. mimicking DMM and as a possible alternative pathway, based on the competitive solubilization of CH and PS, to reduce solubilized CH transport levels from the ME. The effects of different CH/PS ratios, aq. diln., and lecithin-based MEs on sterol crystn. were studied. The pptd. crystals from the ME-loaded system with PS alone and from that loaded with 1:1 or 1:3 CH/PS mixts. were significantly influenced by ME microstructure and by diln. with aq. phase (X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) results). No new polymorphic structures were detected apart from the corresponding sterol hydrates. Mixed crystal morphol. and the habit of the pptd. sterols were strongly affected by the CH/PS ratio and the structures of the dild. ME. As the amt. of PS in the mixt. increased or as the ME aq. diln. proceeded, pptd. crystal shape became more needle-like. The mixed sterols seemed to be forming eutectic solids. [on SciFinder(R)]