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July 8, 1983

And for now: two innovative methods

JAMA. 1983;250(2):145-147. doi:10.1001/jama.1983.03340020003002

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Two seemingly common forms of medication—a cough syrup and a plain blue tablet—represent two of the most recent innovations in oral controlled-rate drug delivery systems.

The cough syrup, Delsym, in which dextromethorphan is the active ingredient, is the first representative of the Pennkinetic system to reach the market. In this system, developed by Pennwalt Corporation, Rochester, NY, a drug in an ionic state is bound to a polymer matrix. Some of the drug/polymer complex is subsequently coated with ethyl cellulose. Then a mix of coated and uncoated particles, which average about 100 μm in length, is suspended in a syrup.

A patient taking a single one-teaspoon dose of the syrup swallows approximately 1 million drug/polymer particles. The drug remains unavailable until it reaches the gastrointestinal system, but once there, ions present in digestive fluids diffuse through the ethyl cellulose coat (if it is present) and bind with the polymer, displacing