C
max is the maximum (or peak)
serum concentration
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', ''molar concentration'', '' number concentration'', ...
that a drug achieves in a specified
compartment
Compartment may refer to:
Biology
* Compartment (anatomy), a space of connective tissue between muscles
* Compartment (chemistry), in which different parts of the same protein serves different functions
* Compartment (development), fields of cells ...
or test area of the body after the drug has been administered and before the administration of a second dose.
It is a standard measurement in
pharmacokinetics.
Description
C
max is the opposite of
Cmin, which is the minimum (or trough) concentration that a drug achieves after dosing. The related pharmacokinetic parameter t
max is the time at which the C
max is observed.
After an intravenous administration, C
max and t
max are closely dependent on the experimental protocol, since the concentrations are always decreasing after the dose. But after oral administration, C
max and t
max are dependent on the extent, and the rate of drug absorption and the disposition profile of the drug. They could be used to characterize the properties of different formulations in the same subject.
Short term drug
side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s are most likely to occur at or near the C
max, whereas the therapeutic effect of drug with sustained duration of action usually occurs at concentrations slightly above the C
min.
The C
max is often measured in an effort to show
bioequivalence
Bioequivalence is a term in pharmacokinetics used to assess the expected in vivo biological equivalence of two proprietary preparations of a drug. If two products are said to be bioequivalent it means that they would be expected to be, for all ...
(BE) between a generic and innovator drug product.
According to the FDA, drug quality
bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation.
By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...
(BA) and BE rely on pharmacokinetic measurements such as
AUC and C
max that are reflective of systemic exposure.
See also
*
Cmean (pharmacology)
*
Area under the curve (pharmacokinetics) In the field of pharmacokinetics, the area under the curve (AUC) is the definite integral of the concentration of a drug in blood plasma as a function of time (this can be done using liquid chromatography–mass spectrometry). In practice, the d ...
References
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Pharmacokinetic metrics