Radiopharmacist's Notes · µ DDS-A™
When CRP is down and µ DDS-A takes over —what changes, what doesn\'t.
A backup dispenser only adds value if the failover is clean — clear about what changes, what stays the same, and what has to be documented on the batch record. This page lays out the three columns of a CRP → µ DDS-A failover. It is a workflow scaffold, not a substitute for your site SOP — the per-step authorisations come from your local QA team.
What the failover means for your workflow
Three columns. The first should be the longest — most of the workflow doesn\'t care which dispenser is in use. The third should never be empty — equipment substitution is always a documented event.
Stays the same
- The host cell — typically FLEX — still provides shielding, Grade A environment and AERB-licensed enclosure
- The synthesised F-18 bulk product (FDG / NaF / F-DOPA / PSMA-1007) coming from SYNT is unchanged
- The unit-dose target activity per patient and per appointment slot
- The downstream syringe transport to the injection room
- QC release process (radiochemical purity, sterility, endotoxin) by the radiopharmacist
Changes
- Dispensing module: CRP → µ DDS-A (different controlled-system instance)
- Output format: µ DDS-A primarily produces shielded syringes; CRP can do open and closed vials
- Volume-precision spec: CRP <1% (Tema-guaranteed); µ DDS-A spec not published on the manufacturer page — confirm via brochure for your validation
- Operator workflow at the control PC — µ DDS-A interface is its own
- Calibration cross-checks at the start of the failover shift
Must be documented
- Batch record annotation: dispense executed on µ DDS-A (not CRP), with start time of the failover
- Deviation log entry per the site SOP — equipment-substitution is a planned deviation, not an unplanned one
- Operator initials on the µ DDS-A run
- Annex 11 audit-trail entry for the configuration-change event
- Return-to-primary record when CRP is back in service
Four rules to live by
- µ DDS-A must be calibrated and verified before being put into the failover role — not assumed-good just because it's sat idle.
- Switching between CRP and µ DDS-A is a planned deviation. Site SOPs should pre-approve the switch as a routine maintenance scenario, not a free-form judgement call.
- Manual-backup mode of µ DDS-A is a third tier of redundancy. It exists. It is not the default. Treat manual-mode dispenses with the same QA discipline as automated dispenses.
- The patient-side workflow does not see the change. If the injection room is told that today's syringes "look different," something has gone wrong upstream — investigate.
Sources: µ DDS-A + CRP product pages; EU GMP Annex 11 audit-trail expectations.
Scope of this page
This is a workflow framework, not a regulatory document. Site SOPs and QA pre-approvals sit with the radiopharmacy programme. The µ DDS-A volume-precision specification is not published on the (the manufacturer )public product page — confirm it via the gated brochure or via Saxsons before validating µ DDS-A as the equivalent-to-CRP fallback. TheFLEX compliance postsets out the full GMP stack the failover sits inside.
Sources cited on this page
- the manufacturer.µ DDS-A — automatic dose drawing system. Manufacturer product page.temasinergie.com ↗
- the manufacturer.CRP Radiopharmaceutical Dispensing System.temasinergie.com ↗
- European Commission.EudraLex Vol. 4 Annex 11 — Computerised Systems.EC text ↗