Modafinil is selectively delivered to the brain, minimizing delivery to the blood, of a person in need thereof by administering to the person a therapeutically-effective dosage of modafinil, wherein the dosage is less than 1 mg, formulated in a lipid microemulsion (LME) and selectively delivered to the upper third of the nasal cavity. The method may be implemented with an intranasal pharmaceutical delivery device loaded with a modafinil composition and adapted to deliver the dosage to the upper third of the nasal cavity.