The stick-up occurred at 4 a.m. Wednesday at the CVS on State Road 67.
Richhart said the robbers loaded the drugs from a locked vault into a blue nylon athletic bag and were gone within five minutes.
"They knew where the items were kept at. They knew what they were in there for. They gave the appearance maybe they had done this in the past."
Richhart said his department is checking with police in Plainfield and Greenfield where there have been similar robberies of other CVS stores.
"Obviously these guys are not only a danger because they're displaying weapons but also the kind of drugs they stole, with those being out on the streets, those are also a danger and a concern to us."
Richhart describes the suspects as white males, approximately 5'8" with slender builds.