Abstract: The invention relates to a controlled-release composition for a biologically active material, wherein said active material has been dissolved or dispersed in an L2-phase comprising(a) at least one monoglyceride of an unsaturated fatty acid having 16-22 carbon atoms or a vegetable or animal oil containing such a monoglyceride,(b) at least one triglyceride of at least one unsaturated fatty acid having 16-22 carbon atoms or a vegetable or animal oil containing such triglycerides and(c) at least one polar liquid selected from the group consisting of water, glycerol, ethylene glycol and propylene glycol. Such L2 phases are known per se but are novel in this context.The composition is prepared by forming the L2 phase and adding the biologically active material before, during or after the formation of the L2-phase. For sensitive substances such as proteins a mixture of the mono- and triglycerides is added dropwisely to a solution of said substance in the polar liquid.