Kansas City, Mo. ? Thieves who took more than 100 pounds of a chemical compound from a pharmaceutical plant could use it to make millions of dollars worth of methamphetamine, police said.

The thieves broke into Sanofi Aventis Pharmaceuticals in south Kansas City on Sunday night and drove off with a barrel containing the compound, which police said was enough to make 400 pounds of methamphetamine with a street value of $28 million.

The two men also stole a white GMC flatbed truck with the words “Midwest Mechanical Contractors” on both sides.

Darren Snapp, a police spokesman, said the men handcuffed a security guard after entering the company, but the guard was able to call police from a cell phone.

The two men then fled with the truck and the compound, which is a key ingredient in many cold medicines.