FDA has released a final guidance describing cGMP for preparing media fills for validation of aseptic preparations for positron emission tomography (PET) drugs. Most PET drugs, which are used for imaging, are given parenterally, and produced by aseptic processing. PET drugs came under the auspices of FDA relatively recently, with the passage of the 1997 Food and Drug Administration Modernization Act, and minimum cGMP standards for this class of drugs were established in 2009. A guidance for preparing new drug applications and abbreviated new drug applications for PET drugs was issued in March 2011, and in comments to the March 2011 guidance and in questions raised at the public meeting, stakeholders requested that FDA provide guidance on media fills for validation of aseptic preparation for PET drugs. This most recent guidance is designed to help manufacturers of PET drugs comply with FDA regulations.

A media fill is a simulation of the aseptic process in which vials are filled with microbial growth medium instead of drug product to test whether the aseptic procedures are adequate to prevent contamination during actual drug production. The guidance document outlines the design of a media fill simulation, describes an example of an appropriate growth medium that can be used, and recommends how often a media fill should be done. In addition, the document provides guidance for qualifying growth media, including the performance of growth promotion tests to test whether the medium is capable of supporting microbial growth. Finally, the guidance describes positive controls for the media fill simulation.