Saxsons Group

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

  1. µ DDS-A must be calibrated and verified before being put into the failover role — not assumed-good just because it's sat idle.
  2. 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.
  3. 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.
  4. 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. The FLEX compliance post sets 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 ↗

Knowledge Hub →

µ DDS-A in plain English

Why the backup dispenser matters and how it sits in the cyclotron radiopharmacy stack.

Sibling →

FLEX — cyclotron GMP stack

Full Annex 3 + Annex 1 + Annex 11 + AERB requirement set the failover sits inside.