The FDA provides "information" on this question in a Warning Letter. The FDA prohibits such manufacturing, of course, because of the risk of cross-contamination and wants to see the following:
A confirmation whether non-pharmaceutical products are supposed to continue to be manufactured - and if so, how the separation from pharmaceutical production is to be carried out.
A risk assessment for all medicinal products manufactured on the shared equipment. The potential contamination from equipment sharing will need to be assessed. Plans are also required to address product quality and patient risk for any product in distribution (including potential recalls or withdrawal of marketing authorisation).
A retrospective evaluation of cleaning effectiveness for dedicated equipment, with a focus on cross-contamination hazards. Consideration should be given to identification of residues, other equipment, piping, storage tanks that may not have been properly cleaned. The assessment should identify any inadequate cleaning procedures for equipment on which more than one product is manufactured.
A CAPA plan that shows how in routine manufacturing the control of manufacturing should be carried out. The plan should ensure that equipment and premises defects are detected, repairs are carried out and appropriate maintenance intervals are in place.
A CAPA plan based on retrospective review of cleaning operations with suggested improvements including timelines for implementation. A description of improvements to the cleaning programme, including improvements to cleaning effectiveness and ongoing cleaning verification.
A summary of updated work instructions to ensure that an appropriate cleaning process verification and validation programme is in place.