Biomedical Engineering: Bridging Medicine and Technology 1st Edition by Veronique Tran,Mark Saltzman

Exercise 1

A drug has a diffusion coefficient in the brain of 10−8 cm2/s and it is eliminated from the brain with a half-life of 45 minutes. If you design an implantable drug-delivery system-a sphere with a diameter of 1 cm-how large a region of the brain can this delivery system treat?