The manufacturer of the painkiller OxyContin is trying to extend its exclusive rights to the drug, which is set to go off patent in 2013, The Wall Street Journal reports. Purdue Pharma LP says a reformulated version of the drug may substantially decrease abuse of the opioid.

The company spent $100 million to develop the new version of OxyContin. The courts will decide whether the company can protect its reformulation, the article notes. Purdue Pharma has 16 patent infringement lawsuits pending against 10 makers of generic drugs.

According to the company, the new version of OxyContin, introduced in 2010, is more difficult to abuse than the original pill. The patent on the old drug is scheduled to expire next year, while the patent on the new formulation extends to 2025.

Generic drug manufacturers say they are able to make their own formulations of the drug that are difficult to abuse. The Food and Drug Administration (FDA) is reviewing what safeguards or reformulations generic OxyContin should have. The FDA is expected to announce its ruling by the end of this year. Little research has been done to determine whether reformulated painkillers are more difficult to abuse, the article notes.

The new OxyContin tablets have been hardened to make it more difficult for them to be broken, chewed or crushed. When they are exposed to moisture or dissolved in water, they turn into a thick gel, which makes the drug difficult to snort or inject.

The company points to a 22 percent decline in the street price of the drug from 2010 to 2011, as evidence the new formulation is cutting down on abuse. The number of visits to poison control centers and admissions to addiction treatment programs due to OxyContin have also declined since the drug was reformulated, they said.