A group of executives for OxyContin maker Purdue Pharma have held a United States patent since 2007 for a "self-destructing document and e-mail messaging system."
This patent, filed in 2002, replaced a similar one from 1997 that was meant to destroy documents or email "at a predetermined time by attaching a 'virus' to the document or e-mail message," according to the U.S. Patent and Trademark Office (USPTO)
The original paperwork for this document-destroying system was filed in 1997, a year after the powerhouse painkiller OxyContin hit the market and quickly proved itself to be a blockbuster drug.
The patent's existence was revealed during the March 8 videotaped deposition of Purdue Pharma's former chairman and president Richard Sackler, whose family owns the pharmaceutical company. The deposition is part of a multi-district litigation against several opioid manufacturers, including Purdue, and a recently unsealed transcript of it was obtained by ABC News.
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Purdue is currently facing approximately 2,000 lawsuits for allegedly deceptive marketing and contributing to the current U.S. opioid crisis. Individual members of the Sackler family who were involved in the businesses are being sued in a small fraction of these cases.
During the deposition, Sackler, 74, was asked about the company acquiring the patent for the self-destructing message system.
"I haven't thought about this in a long time. I don't...I didn't know that the patent ever issued," he said. "I heard about an application, but, this was...not my idea, if I recall correctly. And I thought it was interesting, but nothing came of it commercially."
Howard Udell, who died in 2013, owned the patent. He was the general counsel for Purdue Pharma for more than three decades. Other names on the patent include Stuart D. Baker, a partner at law firm Chadbourne & Parke who was an outside counsel and member of the board of directors at Purdue, and Cary Kappel, who was also an outside lawyer for Purdue.
The system involved a virus that would automatically attach to files as they were created, containing code which would tell "the computer to overwrite and/or delete the file to which the virus is attached at a desired time. Since the virus is attached to the file, it will travel with the file even when the file is copied, forwarded, or saved to disks or tape drives," according to the USPTO filing.
"An effective document retention policy is also valuable in the context of litigation," the patent filing states. "For example, if a business document retention policy states that letters are to be retained for a period of three years, and if it consistently follows this policy, it will be less vulnerable to a charge that a particular 5-year-old letter was destroyed because the letter was harmful to the business litigation position."

PHOTO: Purdue Pharma L.P. OxyContin medication sits on a pharmacy shelf in Provo, Utah, Aug. 31, 2016. Bloomberg via Getty Images, FILE

Purdue Pharma L.P. OxyContin medication sits on a pharmacy shelf in Provo, Utah, Aug. 31, 2016.

When Sackler was asked if the patent was assigned to Purdue Pharma after it was issued, he said, "I didn't know that, but that's what it says. If it says that, that's what it says," as he looked at a document from the USPTO.
The exchange that immediately followed was redacted.
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In May 2007, Purdue pleaded guilty to criminal charges for misleading regulators, doctors and patients about the dangers of opioid addiction. The pharma company paid a $634 million fine. Remarkably, three executives agreed to pay $34.5 million in fines, including Udell, former president Micharl Friedman and former medical director Dr. Paul D. Goldenheim.
In his deposition Sackler was asked if Udell, Goldenheim and Friedman received bonuses that year. He said he did not recall.
Purdue Pharma did not immediately comment on the issue of the patent to ABC News.
In his response to the deposition's leak to the media, Sackler's lawyer, David Bernick, continued to defend Sackler's involvement in the alleged scheme.
"As the full historical record is now becoming known, it is clear that Dr. Sackler supported Purdue's action plan for responding to the increasing evidence of widespread OxyContin® abuse and diversion," he said in a statement.
"That plan not only included cooperating with and following the instructions of public health authorities, but it went further to voluntarily undertake extensive efforts to prevent abuse and diversion of prescription opioids," the statement continued. "The legal allegations relating to Dr. Sackler that have been exhaustively reported in the media starkly conflict with this growing factual record."
About 130 Americans die every day due to an opioid overdose, according to the Centers for Disease Control and Prevention.
The plaintiff's lawyers did not immediately respond to a request for comment.