This video is the third in the Pharmacokinetics series. It introduces Distribution, the D in the four elements (ADME) of pharmacokinetics. It describes how drugs distribute between different body compartments, and the concept of Volume of Distribution (VD).
Next Lesson: MetabolismThis talk is really more of an overview, and the details are not necessarily required to be known. Dose calculation software (like DoseMe) will take care of this.
Also, it should be noted that (dependent on the drug) considering more than one compartment may not even be necessary to determine a required dose.