The term “cross contamination” is used in the pharmacy trade to mean that somehow a second unintended drug has been issued or mixed with the primary (scripted) drug and, thereby has contaminated the primary drug.
This can happen in a wide variety of ways. Even the basic manual pill counting tray is prone to cross contaminating as all pills are poured onto a common surface to be counted. These trays should be cleaned frequently.
The pour-through counter suffers from the same problem; every pill hits in a common area and goes down a common chute, therefore every surface that comes in contact with pills should be cleaned often. Cleaning these units is a much greater chore than cleaning the pill counting tray as disassembly of parts is required.
When counting with a TORBAL Pill Counting Scales and pouring directly into a vial cross-contamination is completely eliminated, as tablets never come in contact with any parts of the unit. The robotic Cassette Systems with individual counting modules also appear to be free of cross contamination problems, as drugs can be placed directly into patient's vial.
Below is an example of cross contamination caused by uncoated generic brand tablets. The residue shown was left after a single pour of 1000 pills. Tablets were poured onto a black foam-board surface from the height of approximately 3 inches.