Hillary Clinton has turned her focus toward the problem of widespread addiction to painkiller drugs, but she has failed to mention that she has taken money from the family that turned the invention of OxyContin into a $14 billion fortune.

Clinton has sought to villainize the painkiller industry in recent days, voicing support for a proposed tax that would be paid by drug manufacturers for any pain pill sold that uses active opioid ingredients—the most popular of which is OxyContin, a slow-release pill that has been described as "the perfect recipe for addiction" and has been abused by more than 7 million Americans over the past two decades.

The drug was invented by Purdue Pharma, a company purchased by Dr. Mortimer Sackler, a Clinton Foundation donor, and his two doctor brothers, Arthur and Raymond, in 1952.

The already wealthy Sackler family purchased the company as a small drug manufacturer but it became a cash cow once OxyContin was approved by the government in 1995. The Sackler family was selling $1.6 billion worth of product annually through sales of the painkiller alone and now ranks as one of the richest in the world.

Mortimer Sackler died in 2010 but was not the only member of the Sackler family that gave money to the Clintons.

Jonathan Sackler, a son of Dr. Raymond Sackler who now sits on Purdue Pharma's board of directors, contributed $2,300 to Clinton's failed 2008 run for president. His listed employer on the donation was Purdue Pharma.

Jillian Sackler, the widow of one of Mortimer's brothers, has been a political donor for Clinton since her first run for U.S. Senate in 2000. After being a consistent donor to her Senate campaigns—giving $6,800 over eight years—she contributed an additional $4,000 to her 2008 run.

Clinton has seen support from Purdue Pharma this election cycle as well. Robin Abrams, vice president and associate general counsel for the pharmaceutical company, contributed $500 to Clinton's campaign in February. Dora Hughes, a Sidley Austin lobbyist currently working on behalf of Purdue Pharma, has contributed $1,500 to Clinton's campaign.

Clinton has previously stated that "the drug companies" are her enemies. The Clinton campaign did not return a request for comment.

Purdue Pharma is currently in the midst of a public relations nightmare after the Los Angeles Times alleged last week that it has been knowingly misleading the public about OxyContin's ability to relieve pain for 12 hours as its advertised to do.

"The drug wears off hours early in many people, a Los Angeles Times investigation found," the Los Angeles Times wrote. "OxyContin is a chemical cousin of heroin, and when it doesn't last, patients can experience excruciating symptoms of withdrawal, including an intense craving for the drug."

"The problem offers new insight into why so many people have become addicted to OxyContin, one of the most abused pharmaceuticals in U.S. history," according to the report.

Purdue Pharma has focused its marketing strategy for OxyContin on the ability for it to last 12 hours, pushing doctors to prescribe the drug on 12-hour dosing schedules only, according to the investigation.

When patients complained that OxyContin was wearing off quicker, doctors were instructed by Purdue Pharma to prescribe stronger doses rather than advise patients to take the drug at shorter intervals. These more potent doses, of course, increase the likelihood of overdose and death.

"Anything shorter needs to be nipped in the bud. NOW!!" wrote one Purdue Pharma sales manager in a memo to staff. Experts on the issue told the Los Angeles Times that taking a drug like OxyContin at 12-hour intervals is "the perfect recipe for addiction."

Internal documents reviewed by the Los Angeles Times indicate that Purdue Pharma was more concerned about revenue than making sure its drug was being used responsibly. A memo written in 1996 advising sales representatives to get doctors to prescribe higher doses of OxyContin was headlined, "$$$$$$$$$$$$$ It’s Bonus Time in the Neighborhood!"

The deceptive marketing campaign from Purdue Pharma almost came to light in 2004 when it was sued by West Virginia for the excessive payments it was making to the company through state programs. Revealed in the case was the fact that the drug's central claim that it could relieve pain for 12 hours was a hoax.

The judge found that patients were supplementing their OxyContin with other painkillers to bridge the gap between doses and that Purdue could have stopped this by being honest about its drug.

"Most of the patients in the clinical trials required additional medication, so called ‘rescue medications,’ that accompanied their 12-hour OxyContin dose," the judge wrote in his 2004 ruling. "Plaintiff’s evidence shows Purdue could have tested the safety and efficacy of OxyContin at eight hours, and could have amended their label, but did not."

Purdue was represented in the case by Eric Holder, who would years later serve alongside Hillary Clinton in the Obama administration. Holder agreed that Purdue would give $10 million to West Virginia to be spent on programs to alleviate drug abuse.

In return, all the evidence uncovering Purdue's dangerous marketing of OxyContin remained sealed and despite the judge's opinion that Purdue should amend its labeling of the drug, nothing was changed.

In 2014, 80 percent of the 5.4 million individuals prescribed OxyContin were taking the drug on a 12-hour schedule. More than half of the drug users were being prescribed doses far beyond what is deemed safe by the Centers for Disease Control and Prevention.