Interpretation 3.5 under Section C.02.007 Sanitation specifies that “a cleaning procedure requiring
complete product removal may not be necessary between batches of the same drug”. The frequency and type
of cleaning for equipment and premises must address the length of time between consecutive lots with the
ultimate goal that a particular lot won’t be contaminated by the previous lot or the environment. It must also
ensure that residual quantities of the previous lot won’t impact on the quality of the following lot. Thus, a
partial cleaning would be required between two lots of the same product, especially for forms such as liquids
or suspensions, in order to prevent a few units at the beginning of a new lot from being filled with residual
quantities from the previous lot that may be located in equipment such as hoses or pumps. A procedure
should be established to ensure adequate removal of residual quantities from the previous lot and validation
available for the maximum period of time between two successive lots in order to avoid problems such as
microbial contamination, accumulation of residue, or degradation of product. The number of lots of the same
product which could be manufactured before a complete/full cleaning should be determined.
