Influence of Glycerol on the polymorphic Behavior of solid Triglyceride Nanoparticles stabilized with Poly(vinyl Alcohol)

Colloidal dispersions of lipids, e.g. triglycerides, are under intensive investigation as drug delivery systems. Solid triglyceride nanoparticles exist in different polymorphic modifications. The aim of this study was to investigate the effects of the addition of glycerol, which can be used for the isotonization of such dispersions, on the polymorphic behavior of poly(vinyl alcohol)-stabilized tripalmitin nanoparticles. Glycerol was added to the nanoparticle dispersions at different concentrations in the heat.
The dispersions were investigated for their thermal behavior and storage stability with regard to particle size and polymorphic transitions of the triglyceride matrix, using photon correlation spectroscopy, differential scanning calorimetry and X-ray diffraction. The addition of glycerol led to a decreasing crystallization temperature of the nanoparticles and slowed down the polymorphic transition into the stable β-modification.