The dosing interval is the period of time between administration of doses.

A first-order process is a process that has a rate proportional to the amount of the reactant involved in this process.

For example, if the drug elimination rate is proportional to the amount of the drug in the body, this means that this drug is eliminated by a first-order process. The proportionality constant is the first-order elimination rate constant. i.e.

Elimination rate = elimination rate constant x drug amount

The rate of drug elimination decreases with the time because the amount of the drug decreases with time.

Assumptions: Elimination is first-order, and the drug is given at fixed intervals(τ)

AMax ss is the maximum amount of drug in the body at steady state. This is the amount of the drug right after IV drug administration (amount).

The volume of distribution is the apparent volume in which the drug can be distributed in. It is the factor that relates the amount of drug in the body to the concentration of the drug in the sampling site. It is not an actual volume, however it is a hypothetical volume determined by the drug distribution behavior.

The volume of distribution ranges from 3-5 liters to more than 25L/kg. Drugs with higher affinity for tissues, have higher volume of distribution.

CpMax ss is the maximum amount of drug in the body at steady state. This is the amount of the drug right after IV drug administration (amount).

Cpmax ss is the maximum drug concentration at steady state. This is the drug concentration right after IV drug administration (amount/volume).

Cpmin ss is the minimum drug concentration at steady state. This is the drug concentration right before drug administration (amount/volume).