“Absence of Specified Microorganisms” versus “Absence of Objectionable Microorganisms” of the Microbial Limits Tests for Non-Sterile Pharmaceuticals

Different types of Microbial Limits Tests have been introduced and implemented since the outbreaks of microbial diseases in the 70’s due to the uses of medications contaminated with unexpected pathogenic organisms. The tests were designed to ensure a product is safe for use. The monographs described in the official compendia, however, are merely the minimal requirements and should not be taken as proof that the product is suitable for sale from a microbiological perspective. In this article, the differences between “Absence of Specific Microorganisms” and “Absence of Objectionable Microorganisms” are highlighted and discussed.