Q Is the periodic re-evaluation of disinfectant efficacy useful in any way? I have been asked to repeat these studies even
though they have been done in the past. There's been no change to the materials or methods since that time.
A In the pharmaceutical manufacturing industry, operating under GMPs, the periodic revalidation of disinfection efficacy is
not scientifically justified or required provided the disinfectant used remains the same, the dilution of the disinfectant
is still the same, the challenge organisms (including environmental isolates) are still the same, the manufacturing environment
surfaces are still the same and the vendor for the disinfectant is still the same. To my knowledge, only when one of these
five elements regarding cleanroom disinfection is changed are you required to repeat the validation of disinfection efficacy
testing. Periodic revalidation of a disinfectant serves no useful scientific purpose and I do not know of an FDA regulation
that states that one must periodically revalidate disinfectants. Be sure to execute the disinfection efficacy validation properly
and have complete documentation.
John S. Kent
John S. Kent, PhD
Principal, Pharmaceutical Development Consulting
San Mateo, CA (USA) 94403