Liquid crystalline particles consisting of glycerol dioleate (GDO) / soy phosphatidylcholine (SPC) mixture and stabilised by polysorbate 80 (P80) have proven to be suitable as drug delivery vehicles. Hower their internal structure and location of the different compounds is still not fully understood. Previously SANS study on SANS2D allowed us to determine the location of P80 within the particles. Phase separation occurs at high P80 fractions and the surface layer becomes richer in both solvent and d-P80 and the core of the particle is suggested to be enriched in GDO. This gives loss of internal structure and reduced hydration. However the scattering length density of hydrogenated GDO and SPC is very close so we cannot verify this. The aim of the present study is to determine the content of GDO in the core and shell as a function of the P80 content by using chain deuterated GDO.