in 1995, purdue pharma laboratory tests showed that "68% of the oxycodone could be extracted from an oxycontin tablet when crushed". a july 1996 study co-authored by paul d. goldenheim md - who later became purdue's chief medical officer - published in the "journal of clinical pharmacology" reported that the controlled-release (cr) formulation - by mouth - had a variable duration of action ranging from 10–12 hours. the report by eight authors said that, "[t]reatment with cr oxycodone was safe and effective in this study, and its characteristics will be beneficial in the treatment of pain." the report said that the study was independent of purdue pharma.