Bioburden

The number of viable microorganisms on or in a material, intermediate or product, typically before sterilization or sterile filtration. Bioburden is controlled because it challenges the sterilizing filter, can generate endotoxin and indicates whether a process is under control. Japanese specifications set bioburden limits at defined process steps, and the Japanese Pharmacopoeia has general tests for the microbiological examination of non-sterile products. A result within the limit but unusual for that step deserves a look before it becomes a trend.