Abuse-resistant controlled-release opioid dosage form

Abstract

Abuse-resistant, controlled release opioid tablets are a combination containing an opioid antagonist such as naloxone at a level that needed to suppress the euphoric effect of the opioid, if the combination were crushed to break the controlled release properties causing the opioid and opioid antagonist to be released as a immediate release product as a single dose. The controlled release nature of the table prevents the accumulation of orally effective amounts of opioid antagonist when taken normally. The opioid antagonist is contained in a controlled-release matrix and released, over time, with the opioid.

Description

[0001] This application claims benefit of priority to U.S. Provisional Application No. 60 / 290,439 filed on May 11, 2001.[0002] The present invention relates to controlled-release analgesic pharmaceutical formulations. More specifically, the invention relates to abuse-deterring controlled-release analgesic tablets.BACKGROUND OF THE RELATED ART[0003] Opioid compounds have long been known both for their powerful analgesic properties, and for their strong potential for abuse. While highly effective at controlling pain, opioids can also be addictive. Abuse of opioids, particularly heroin, but also including morphine, codeine, oxycodone, hydromorphone, oxymorphone, and others, is a problem in modem society. Opioid addicts can obtain drugs from a variety of illicit sources. These street drugs are of questionable quality. Therefore, to potential abusers, prescription pharmaceutical opioids can be particularly attractive as a drug source because of their high purity and dependable dosage.[00...

AI Technical Summary

Benefits of technology

[0012] Abuse-resistant, controlled release opioid tablets are a combination containing an opioid antagonist having a high oral:parenteral potency ratio (i.e. oral:parenteral>1), such as naloxone, at a level insufficient to block the opioid effects or to attenuate the opioid side-effects in the controlled release formulation administered over an extended period, but above that needed to suppress the euphoric effect of the opioid if administered all at once. If the combination tablet is crushed to break the controlled release properties, the opioid and opioid antagonist is released as an immediate release product in a single dose, and the antagonist blocks the euphoric effects of the agonist. The opioid antagonist is contained in a controlled-release matrix and released over time, with the opioid agonist.

Problems solved by technology

Opioid compounds have long been known both for their powerful analgesic properties, and for their strong potential for abuse.

While highly effective at controlling pain, opioids can also be addictive.

Abuse of opioids, particularly heroin, but also including morphine, codeine, oxycodone, hydromorphone, oxymorphone, and others, is a problem in modem society.

These street drugs are of questionable quality.

To do so, the tablets are crushed and often dissolved.

Naloxone is highly effective when taken parenterally, but poorly effective when taken orally because of its metabolism in the liver and, thus, has a high oral:parenteral potency ratio.

Because antagonists such as naloxone are less effective when taken orally, they have not been used to deter oral abuse and have been limited to deterring parenteral or intranasal abuse.

Prior oral opioid dosage formulations contained relatively low doses of opioid and were not generally targets for oral abuse.

Their immediate release formulations release the opioid all at once, but with low amounts of opioid that would not be sufficient for oral abuse without putting several low dosage units together.

The antagonist is present and released in amounts, over time, that attenuate or reduce the side effects of the opioid agonist, yet in amounts insufficient to block the opioid effect.

However, if the antagonist is administered all at once, it will block the opioid effect and may induce withdrawal in dependent individuals.

Antagonists need to reach an effective dose to work, so their slow release coupled with fast metabolism means they are maintained at ineffective, low levels in normal, recommended, therapeutic, non-abusive use.

Under normal conditions, the release rate is not sufficient for blocking the opioid effect nor suitable for selectively blocking the excitatory opioid receptors to attenuate opioid side effects.

Thus, effective parenteral / intranasal doses are ineffective when administered orally.

The high oral:parenteral potency ratio antagonists, such as naloxone, while very effective when injected, are significantly less effective when taken orally.

Such an antagonist would be effective in deterring intravenous or intranasal abuse when present in low levels, but would be ineffective in deterring oral abuse.

Were the tablets to include sufficient antagonist to deter oral abuse, the antagonist would also reduce or inhibit the therapeutic efficacy of the drug.

Although this type of arrangement would be beneficial in many situations, it could limit a prescribing doctor's options, and therefore, may not be appropriate in all situations.

From these tests, it is evident that under normal, non-crushing use, the amount of antagonist, here naloxone, released over time is insufficient to block the opioid effect.