1. DRUG
The drug is in direct contact with release liner.
Ex: Nicotine, Methotrexate, and Oestrogen.
Some of the desirable properties of a drug for
transdermal delivery:
1. The drug molecule should possess an adequate
solubility in oil and water.
2. The drug should have a molecular weight less than
approximately 1000 daltons.
3. The drug should have low melting point.