The invention refers to the use of an inert, structure-giving, deadjuvanated matrix of a complex of a sterol, such as cholesterol, and one or more saponins as a carrier for the administration of a pharmaceutically active substance, and a drug carrying particle comprising said inert structure-giving matrix to which has been connected a pharmaceutically active substance. The drug carrying particle, delpha, has an annular basic structure which can form spherical nano particles having a size of 30-50 nm and a narrow size distribution.