Cmin is a term used in pharmacokinetics for the minimum blood plasma concentration reached by a drug during a dosing interval, which is the time interval between administration of two doses. This definition is slightly different from Ctrough , the concentration immediately prior to administration of the next dose. Cmin is the opposite of Cmax , the maximum concentration that the drug reaches. Cmin must be above certain thresholds, such as the minimum inhibitory concentration (MIC), to achieve a therapeutic effect. In most cases Cmin is directly measurable. At steady state the minimum plasma concentration can also be calculated using the following equation: ke = Elimination rate constant ka = Absorption rate constant Vd = Volume of distribution Cmin is also an important parameter in bioavailability and bioequivalence studies, it is part of the pharmacokinetic information recommended for submission of investigational new drug applications.