Tiny Transporters Deliver Pain Relief

Osteoarthritis drugs for the knee last longer when delivered with nanoparticles

(RxWiki News) Arthritis drugs can be effective if given enough time to work. But the drugs often leave the body before their job is done. Finding a way to make arthritis drugs last longer could mean better results and fewer injections.

Doctors may be able to use tiny particles - called nanoparticles - to deliver osteoarthritis drugs to the knee joint. These nanoparticles could help the drugs last longer in the knee cavities of arthritis patients.

"A new arthritis drug could benefit patients, ask your pharmacist."

One of the bigger difficulties in treating osteoarthritis is the short length of time that arthritis drugs stay inside the affected joint. Michael Morgen, Ph.D., and his fellow researchers from Bend Research and Pfizer thought that injecting drugs with nanoparticles would keep drugs in the knee joint for longer periods of time.

They found that the nanoparticles do make the drugs last longer.

At the moment, there are no drug treatments that stop arthritis from progressing. However, patients can take drugs that relieve symptoms such as pain. The problem is that these drugs cannot stay in the body long enough to provide real relief to patients.

Dr. Morgen and colleagues may have found a way to fix that problem. When using nanoparticles to inject arthritis drugs into the knee joint, Dr. Morgen and colleagues found that 70 percent of the drug nanopartcles stayed in the body for at least a week. By comparison, most current injections last only a day or two.

In addition to being more effective, longer lasting arthritis drugs allow patients to get injections less frequently - injections every three months instead once every week.

The nanoparticle injections work by carrying a drug to molecules in the knee. When these particles meet, they form a gel that slows the release of arthritis drugs from the knee.

While these findings may be promising for arthritis sufferers, it should be noted that the study has only been presented at an academic meeting. The study still needs to go through a peer-review process to make sure its methods and findings are reliable.

According to Dr. Morgen, the current ways to deliver arthritis drugs do not stay in the knee for very long, which makes those drugs much less effective. Having longer lasting drugs may mean that patients get more relief with fewer injections.

The research by Dr. Morgen and colleagues is being presented at the 2011 American Association of Pharmaceutical Scientists (AAPS) Annual Meeting and Exposition in Washington, D.C.

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Review Date: 
October 26, 2011