Sec. 425.400 Computerized Drug Processing; Input/Output Checking (CPG 7132a.07)
BACKGROUND:
Section 211.68 (automatic, mechanical, and electronic equipment) of the Current Good
Manufacturing Practice Regulations requires, in part, that input to and output from the
computer or related system of formulas or other records or data be checked for accuracy.
This requirement has generated questions as to the need for and extent of checking a
computer's input and output.
The agency received several petitions to delete or modify the requirement on the
grounds that a validated computer system need not have its input/output routinely checked.
The request to delete or modify the requirement was denied because our experience has
shown that input/output error can occur, even in validated systems. Printouts, for
example, can contain errors as a result of faulty input, programming, or equipment
malfunction. More significantly, there is the human element which can induce errors. At
worst, input/output errors can result in serious production errors and distribution of
adulterated or misbranded products. Several recalls have, in fact, been conducted because
of insufficient input/output checks.
Despite the general need for input/output checks, not all input and output need be
checked. The regulation is, in fact, deliberately silent on the required frequency and
extent of data checking to afford firms the necessary flexibility. Also, the use of
efficient input edits, for example, could mitigate the need for more detailed manual data
checks.
POLICY:
Input/Output checks of data for computer systems, as required by 21 CFR 211.68, are
necessary to assure the quality of a drug product processed using such systems. The extent
and frequency of input/output checking will be assessed on an individual basis, and should
be determined based upon the complexity of the computer system and built in controls.
Issued: 9/20/82
Reissued: 9/4/87