Human Tissue Authority

The regulator for human tissue and organs

Preparation Process Dossiers guidance

It is a mandatory requirement that the processes used to prepare tissue or cells for patient treatment (human application) do not render them clinically ineffective or harmful, and they must be validated.

The validation of the processes may be based on:

  • An establishment’s own studies;
  • Data from studies published by others with operation validation; or
  • A retrospective analysis of clinical outcomes.

The HTA has adopted the Preparation Process Dossier (PPD), as recommended by the European Commission, to assist its review of process validation. We may ask you to complete a PPD form (Word) for each process you use. It includes information regarding process validation, reagents and materials, quality control and labelling. In addition, you should download the guidance document (PDF) which was updated in December 2015. This guidance should now be used while you are completing the PPD. Please also read the frequently asked questions.


Updated September 2020

Last updated on: 16 Sep 2020