(Reuters) - Intellipharmaceutics International Inc, said on Monday the U.S. Food and Drug Administration (FDA) declined to approve its opioid painkiller in its current form, asking for more proof of the drug’s ability to prevent abuse.

The FDA’s decision comes at a time when the United States is battling an opioid abuse crisis, which claimed more than 33,000 people in 2015, according to the U.S. Centers for Disease Control and Prevention.

In an attempt to combat opioid abuse, federal authorities have implemented a slew of measures to limit the supply of such drugs, especially by requiring drugmakers to prove that their painkillers deter abuse.

President Donald Trump weighed in last month, declaring the opioid epidemic a national emergency and saying his administration was drafting papers to make it official.

Toronto-based Intellipharma’s drug, Oxycodone ER, which is designed as a unique, abuse-deterrent version of Purdue Pharma’s oft-abused blockbuster OxyContin, contains a blue dye and a nasal irritant meant to help identify abusers and discourage misuse.

The FDA asked Intellipharma to conduct more studies to test the abuse-deterrent qualities of the long-acting drug when used via oral and nasal methods. The agency also requested more information related to the blue dye.

A panel of independent advisers to the FDA, which voted 22-1 against approving the drug in July, had flagged concerns about the dye’s possible toxicity.

Intellipharma’s U.S.-listed shares, down about 68 percent in the last two months, were up about 20 percent at $1.02 on Monday afternoon after the company said it had already planned the additional studies requested by the FDA.

The drugmaker, which has at least one year to comply with the FDA’s requests, said the agency’s decision would not affect Oxycodone ER’s marketing timeline.

Analysts said investors were confident about the drug’s path forward, given Intellipharma’s ability to comply with the FDA’s requests.

A number of U.S. states and local governments have filed lawsuits against opioid drugmakers and wholesale distributors holding them accountable for a national drug addiction epidemic.

In June, the FDA called for the withdrawal of Endo International Plc’s Opana ER after a panel of advisers concluded that the opioid painkiller’s benefit did not outweigh its risks. It was the first time the agency had asked for the withdrawal of an opioid for public health reasons.

Endo removed Opana ER from the market a month later.