Dosage form minimum effective concentration

Figure 1.4 A typical plot (rectilinear paper) of plasma concentration versus time following the (oral) administration of an identical dose of a drug via identical dosage form but different formulations. MTC, minimum toxic concentration MEC, minimum effective concentration.

An ideal drug delivery system is one which provides the drug only when and where it is needed, and in the minimum dose level required to elicit the desired therapeutic effects. In practice, such a system should provide a programmmable concentration-time profile that produces optimum therapeutic responses. This goal can only be achieved to a limited extent with conventional dosage forms. 

Many chronic conditions are most effectively treated via MR oral drug delivery, mainly due to the fact that the number of required daily doses can be reduced to one or two, thus facilitating convenience and compliance. APIs exhibiting narrow therapeutic indices can be formulated into oral MR dosage forms in order to prevent API concentration spikes in the blood above that of the minimum toxic concentration (see Figure 27.3). 

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