I'm looking for some thoughts on a strategy for maintaining the blind for placebo-controlled study where the IMP (licensed, widely available drug, but different indication) and placebo are made up by local staff in A&E...

To summarise:
- Unblinded staff will randomise to determine treatment allocation.
- Unblinded staff will then make up the IMP/placebo (a dilution of IMP in saline or pure saline) and present a 10ml, colourless solution in a syringe for administration by blinded staff.
- Accountability and a record of treatment allocation will be recorded and stored with the IMP in a locked cupboard in the department. This log will then be removed daily (by unblinded research nurse) to be retained in the ISF.

I'm still ironing out exactly who needs to remain blinded, but just put my feelers out there to see if anyone has any experience of maintaining the blind in any setting (but particularly A&E) with partially blinded/unblinded staff. This is a non-commercial, single site study with limited funds so no option for pre-filled pre-labelled syringes.

Likewise, if this process seems sensible, then feedback on that will be appreciated.
Thanks in advance!