Investigation on the viscoelastic properties of lipid based colloidal drug carriers.

The rheological behaviour of solid lipid nanoparticle dispersions (SLN) prepared by high pressure homogenization was investigated using a Haake RS-100 rheometer. Four preparations differing in their lipid content and macroscopic consistency were tested by continuous shear rheometry and oscillatory testing. Rheological data from continuous shear measurement reveal plastic flow for systems with low lipid content as well as for systems with high lipid content. By using oscillatory testing more detailed information concerning the structure could be achieved. Rheological measurements of 40% lipid dispersions show viscoelastic properties comparable to the data from standard dermal preparations. Therefore high concentrated lipid dispersions might constitute a promising vehicle for topical administration.