Interne Qualitätskontrolle, often shortened to IQK, is the part of quality assurance a pharmacy carries out on its own equipment, on its own schedule, without anyone outside being involved. A Kontrollmaterial with a known target value and an acceptable range is measured on the device exactly as a customer sample would be, and the measured value is compared with that range and written down.
What a control result proves is narrower than it first appears. A control inside its range says that the device, the current reagent lot and the person operating them produced a correct value for that control material at that moment. It says nothing about the sample measured afterwards and nothing whatsoever about the customer. A device can pass every control and still return an unusable value because the sample was haemolytic, mislabelled or badly handled, which is why control work never replaces careful Präanalytik.
The schedule matters as much as the act. Common practice is a control with every new reagent or strip lot, after maintenance or a repair, whenever storage conditions have been in doubt, and at fixed intervals during normal running, with the interval taken from the Gebrauchsanweisung. Whatever the pharmacy settles on is written into its Standardarbeitsanweisung so that the rule does not depend on who happens to be on shift.
A failed control is a stop rather than a note. The device leaves service for that parameter until the cause is found. The usual causes are an expired or poorly stored control material, a new lot handled wrongly, a device needing cleaning or calibration, or a genuine defect. Values measured since the last good control are then reviewed, and if a customer has already been given one, the pharmacy has to decide honestly whether to invite that person back.
Internal control is not the same as external comparison. In a Ringversuch an unknown sample arrives from outside and the pharmacy result is judged against other participants, which is a check against the wider world rather than against the device yesterday. Both belong in the written Qualitätssicherung, next to the operating duties of the MPBetreibV. For a Point-of-Care-Test the pharmacy carries this work itself, while an akkreditiertes Labor runs the same logic on a far larger scale under its accreditation.
This glossary entry is general information about German pharmacy law and practice. It is not legal advice. For binding guidance on your own pharmacy, contact your Landesapothekerkammer.
