The FDA has approved two-cholinesterase inhibitors for mild to moderate symptoms of Alzheimer's disease in the tablet dosage form. Both drugs are administered orally, requiring one or more tablets per day to be taken. This places a daily burden, on the patient to accept medication, and on the caregiver to see that the drug is taken on schedule. The scope of this proposal is to develop a transdermal patch for Alzheimer's patients for one of the cholinesterase inhibitors. Based on the physicochemical and pharmacokinetic parameters of this drug, a successful patch could be developed. The scope of this proposal ranges from concept development to determination of technical feasibility. The feasibility patch development would include screening of adhesives, cosolvents, and skin permeation enhancers. The design of the patch will be matrix type drug-in- adhesive system. The formulations will be selected based on in vitro permeation studies through human cadaver skin, in vitro release studies, and adhesive properties of the patch. Accelerated stability studies will be conducted to evaluate the drug incompatibilities. We expect this transdermal patch would improve the cognitive function of patients by maintaining steady-state plasma levels, would be acceptable by the Alzheimer's patients and caretaker and would improve patient compliance.
The retail cost of the oral medication for Alzheimer's patients is $135 to $150 per 30 tablets ($4.50 to $5.00 per day). The expected retail price for the patch would be about $3.50 for a twice-a-week patch and $7.00 for a once-a-week patch ($1.00 per day). About 5 million Americans inflicting with Alzheimer's disease by year 2005, the expected savings would be enormous. The market potential for this cholinesterase inhibitor patch is very big and real.
