"Mr. Priest stated that they can do accuracy testing for sterile compounding." Well there ya go, it is a given that the admixure is sterile. Mr. Priest does not state "accuracy testing for compounding" nor does he state "testing for sterility". He includes the adverb "sterile" to describe an important condition of the compounding process. They are testing for the compounding accuracy of a sterile admixture. Sterile is a given. It can be interpreted no other sensible way IMO. End of story.