A company investigation turned up metal in roughly 200 pills of the 70 million it passed through a metal detector, according to the FDA.
Passing pills through a metal detector is a good way of ensuring quality control for this issue. 
( z1 way :ARG1-of ( z2 good ) :manner-of ( z3 ensure :ARG1 ( z4 control :ARG1 ( z5 quality ) :topic ( z6 issue :mod ( z7 this ) ) ) ) :domain ( z8 pass :ARG1 ( z9 pill ) :path ( z10 through :op ( z11 thing :ARG0-of ( z12 detect :ARG1 ( z13 metal ) ) ) ) ) )