A, unconstrained free diffusion from packaging materials, or fast dissolution from antimicrobial tablets,
B, slow diffusion of very low solubility agents from monolithic packaging materials;
C, membrane (reservoir) system with constant flux of permeation, slow dissolution from antimicrobial powder/tablets or gaseous agent release from concentrated antimicrobial sachets/tablets with constant volatility in a closed packaging system. Dashed lines and arrows indicate the minimum inhibitory concentration (m.i.c.) of a target micro-organism, and the period of shelf life maintaining the surface concentration over the mic respectively