Two Alachua County men operating a multimillion-dollar internet pharmacy have pleaded guilty to selling drugs without requiring customers to provide a prescription, according to the U.S. Attorney’s Office.

Edward Leonforte, 55, of Gainesville, and Larry Burstein, 69, of Alachua, face a maximum of 20 years in prison when they are sentenced in early 2017, a press release said.

Burstein pleaded guilty to conspiracy Thursday. Leonforte in September pleaded guilty to conspiracy, distribution of the controlled substance codeine and money laundering.

The men operated multiple internet pharmacy websites from rental space in Progress Park in Alachua, federal authorities reported and sold what federal authorities described as "substantial quantities" of prescription drugs.

Between 2013 and 2015, operating as freeworldpharmacy.com, Leonforte’s business sold more than $7.5 million in pharmaceuticals, including more than $385,000 in generic codeine in 2015.

An undercover Drug Enforcement Administration officer was able to order and receive hundreds of codeine pills without a prescription from freeworldpharmacy.com and medsindia.net, the release said.

Codeine is a narcotic used to treat pain. It is also used in small amounts in some cough and cold syrups.

Leonforte is set to be sentenced in federal court in Gainesville on Jan. 4. Burstein is set to be sentenced on Feb. 3.

A joint investigation by the DEA and Internal Revenue Service with assistance from several other local, state and federal agencies led to the arrests.