Solids …….Liquids

The differences in the cleaning of equipment utilized for solid and liquid formulations are
quite significant. The distinction between these formulation types is related to how
contamination might be left on the equipment and dispersed in subsequent products.

Liquid formulations may have greater ability to penetrate equipment seals and joints, hindering their
removal. In contrast, solid formulations may have unique abilities to form aggregations of
product. This "clumping" may inhibit "wetting" by cleaning agents thereby limiting the ability to "rinse" the residual product away.
The "distribution" of the contaminant is often considered to be quite different for solid and
liquid formulations as well. Liquid products are often considered to have superior dispersion
of active ingredients uniformly across surfaces, while solid products are expected to have
more point to point variability, based primarily upon equipment configuration.