Researchers at the Ohio State University (OSU) and the University of Michigan have developed a medicated oral patch that allows a chemoprevention drug to release directly into precancerous lesions in the mouth over an extended time.
In a study in Pharmaceutical Research (June 15, 2011), the researchers evaluated the drug fenretinide, a synthetic derivative of vitamin A that has anticancer properties. Until now, scientists have failed to achieve a therapeutic, systemic dose of fenretinide because of drug toxicity and rapid release from the body.
By using a new mucoadhesive patch invented by a team from OSU's Comprehensive Cancer Center -- Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC-James) and the University of Michigan, the researchers developed a delivery system that can provide continuous drug therapy to saliva-coated oral tissue.
"The challenge with oral gels or rinses is the medication can dissolve in saliva before it penetrates into the tissue. This patch allows us to target and control drug delivery and tissue exposure," stated study author Susan Mallery, DDS, an oral pathologist at the Comprehensive Cancer Center, in a news release.
The patch consists of three layers: a disk saturated with fenretinide and polymers to make the drug more soluble in saliva, an adhesive ring to hold the disk in place, and a backing layer to ensure the medication stays within the patch.
In their study, Dr. Mallery and co-investigator Peter Larsen, DDS, also of OSU, tested the fenretinide patch using simulated saliva and also lab animals. In both situations, therapeutic doses comparable to levels needed in humans were achieved without detection of the drug elsewhere in the system or surrounding healthy tissue.
"These results are very encouraging. Fenretinide is a drug that scientists have studied as a cancer-preventing compound for decades, and with this mucoadhesive patch, we finally developed a way to harness its potential," Dr. Mallery said.
Next, Dr. Mallery and her team of investigators will see if these lab results translate to humans, as they begin treating patients in their dental clinic with the fenretinide patch within about 16 months.
