The present description relates to a liquid composition having at least one immune-modulatory macrolide compound and an essentially cell-free blood hemolysate. The present description further relates to a method for manufacturing a stabilized immune-modulatory macrolide calibration solution, by a) preparing a solution comprising an essentially cell-free blood hemolysate, b) admixing a predetermined amount of at least one immune-modulatory macrolide into said solution comprising an essentially cell-free blood hemolysate, and, thereby c) manufacturing a stabilized immune-modulatory macrolide calibration solution. Furthermore, the present description relates to kits, uses, devices, methods and to an immune-modulatory macrolide compound calibration solution related thereto.
