Can vibrating screen be shared?

A factory produces three kinds of oral solids of traditional Chinese medicine and material is extracted by water and then dried. Afterwards, dried extract is granulated, sieved by vibrating screen, mixed with appropriate amount of magnesium stearate and finally compressed to tablets. Since the extract is extracted by water, it is convenient and easy to clean equipment after production. And no problem is raised during cleaning verification. But as we all know, ingredients of traditional Chinese medicine preparations are pretty complex and we cannot determine the percentage of ingredient residue. Therefore, in the GMP follow-up inspection, the inspector doubts about the feasibility of common use of the screen.

However, why can vibrating screen not be in common-use while other equipment (including the equipment for extracting, drying, granulating, mixing, compressing, coating and blister packing) can.

In fact, the inner surface of equipment is clean and smooth. But the screen is so uneven that some material might remain on it. Besides, the screen meshes of these machines such as grinding machine or sieving machine are micro. It’s difficult for inspector to sample and for operators to clean. Also, different from the inspection for chemical drugs, there is no clear inspection and analysis procedure for traditional Chinese medicine. Anyway, it is not laborious to use one special screen for one machine. So it is suggested to manufacturers to use special screens, just like that special filtering bags are used for fluid bed drying of different medicines.