Abstract: A two-compartment syringe assembly (10) is composed of a first, outer cylindrical barrel (12), a second, inner cylindrical barrel (14). in which a material (66) is enclosed within a capsule part or ampulla (16) which is received and protected within the second cylindrical barrel, a plunger (18) and a liquid (20), which is enclosed within a first compartment defined within the first cylindrical barrel (12). As the material is concealed within the second cylindrical barrel, any risk of leakage of the material to the environment or atmosphere in case the two-compartment syringe assembly is exposed to shocks, such as mechanical blows, is radically reduced as compared to conventional two-compartment syringe assemblies.