The product, called Remoxy (oxycodone), is the most advanced-stage development product to make use of a drug delivery matrix - ORADUR - developed by Durect Corp.
Products based on the ORADUR technology can take the form of an easy to swallow gelatin capsule that uses a high-viscosity base component, SABER or sucrose acetate isobutyrate, to provide controlled release of active ingredients for a period of from 12 to 24 hours of drug delivery.
Oxycodone is the active ingredient in Purdue Pharma's OxyContin, a branded, controlled release narcotic painkiller with annual sales exceeding $1.9 billion that has been the subject of a number of cases of diversion and abuse, according to the US Food and Drug Administration (FDA).
Reports have indicated that abusers crush OxyContin tablets and snort the powder or dissolve it in water or alcohol (vodka apparently being a preferred medium) and inject it to defeat the controlled-release effect of the formulation and attain a "rush" or "high" through the resulting rapid absorption of the drug. It is estimated that this abuse is associated with several hundred deaths a year in the US. ORADUR's liquid matrix formulation makes this rapid release impossible, according to Durect.
The study was designed to compare the safety and efficacy of Remoxy against placebo in osteoarthritic patients with moderate-to-severe chronic pain. Patients were treated with Remoxy 20mg or matching placebo twice daily over a 4-week study period. The results announced by Pain Therapeutics demonstrated a statistically significant percent decrease in pain scores for patients using Remoxy as compared to placebo, and no drug-related safety issues were noted in the study. Pain Therapeutics intends to initiate a second Phase III registration study by year-end 2005.
"These clinical results reinforce our belief that products developed with our ORADUR sustained release oral gel-cap technology may offer a variety of benefits, including the potential to reduce abuse when compared to current long-acting dosage forms that are on the market today," said James Brown, president and CEO of Durect.
Last year, state agencies in the US and Purdue took actions to address the abuse and diversion of OxyContin. The FDA approved a stronger safety warning on OxyContin's label, and the agency and Purdue have collaborated on a risk management plan to help detect and prevent OxyContin abuse and diversion, an approach that was not used at the time the drug was first approved in 1995.
ORADUR-based products can be manufactured by a capsule-filling process using conventional equipment making them readily scalable, according to Durect.