Preparation and labelling of medication to be used in the trial
Tranexamic acid has marketing authorisation in the UK and will be purchased from the open market. Marketing authorisation guarantees that drug manufacture and release comply with Good Manufacturing Practice (GMP). A GMP-certified manufacturer will prepare the matching placebo (sodium chloride 0.9%). Tranexamic acid and placebo ampoules and packaging will be identical. A clinical trial supplies company will conduct the blinding process and first-stage qualified person (QP) release. The blinding process involves replacing the manufacturer’s label with the clinical trial label. Other than the randomisation number (used for pack identification) and route of administration, the label text will be identical on all ampoules and comply with clinical trial requirements. To check the blinding, known tranexamic acid will be compared with blinded samples from a random set of treatment packs to determine which are tranexamic acid. The samples will then be un-blinded to confirm the accuracy of the labelling.