Research needed to develop generic drugs

WASHINGTON, May 2 (UPI) -- The U.S. Food and Drug Administration has issued a report identifying some scientific impediments to development of some new generic drugs.

"This report pinpoints the barriers that are limiting the availability of additional generic drug options," said Gary Buehler, director of the FDA's Office of Generic Drugs. "We hope these findings will encourage research collaboration, lower these barriers and accelerate access to safe and effective generic drugs."

Generic drugs must have the same active ingredient, dosage form, strength, and conditions of use as brand name drugs and must also be absorbed at the same rate and in the same amount -- a concept known as bioequivalence.

While blood plasma levels are sufficient to demonstrate bioequivalence for most generic drug candidates, those tests are not appropriate for some drugs, including asthma inhalers, nasal sprays, and topical skin applications.

The report issued Wednesday calls for research into new bioequivalence methods, including lung function tests and molecular level imaging for inhalation drugs; particle size distribution tests for nasal sprays, and methods for direct measurement of drugs delivered to the skin.