Two University of Kentucky College of Pharmacy faculty members have developed a nasal drug delivery system for Viagra causing the drug to work almost immediately after dosing.
A problem with the Viagra tablet, approved last March for impotency in men, is that it can take an hour or more for the drug to take effect, said Lewis Dittert, Ph.D., professor in the UK College of Pharmacy.
"If a man takes Viagra and gets no response, he may become impatient and after 30 to 45 minutes be tempted to take one or two more tablets, just as the first one is being absorbed," Dittert said. "The result would be an overdose."
Dittert and Anwar Hussain, Ph.D., professor in the UK College of Pharmacy, developed the nasal spray at their company, New Millennium Pharmaceutical Research Inc. (NMPRI) located at Advanced Science and Technology Commercialization Center (ASTeCC) on the UK campus.
The active ingredient in the Viagra tablet is poorly soluble in water and becomes even less soluble when it reaches the small intestine where it is absorbed by the blood, Dittert said.
The advantage of the intranasal route is the drug is transferred directly into the blood without being exposed to the alkaline intestinal fluids. UK researchers also have made the active ingredient into an aqueous solution and made it soluble in water.
Hussain has studied nasal drug delivery systems for more than 15 years and Dittert for more than 10 years.