Disclosed is a method of determining an amount of drug deliverable to a biological subject by an iontophoretic delivery device having a drug holding portion for holding a drug solution including drug ions of a first polarity, an electrode coupled to the drug holding portion and operable to apply an electrical potential of the first polarity to the drug solution held in the drug solution holding portion, and a first ion exchange membrane, having an exchange group of the first polarity, in contact with a front surface side of the drug solution holding portion, the method comprising: determining a first drug migration parameter indicative of the migration of an amount of drug ions from the first ion exchange membrane to an outermost front surface side of the iontophoretic delivery device； determining a second drug migration parameter indicative of the migration of an amount of the drug ions migrated from a volume of a drug ion solution to a plurality of liposome in a volume of a Iiposome suspension after contacting the volume of the drug ion solution to the volume of the liposome suspension； and determining at least one of an iontophoretic drug ion delivery amount, iontophoretic drug ion delivery rate, an efficiency, and a dose based on the determined first drug migration parameter and the determined second drug migration parameter.
