During a Phase I clinical trial of a novel synthetic antiviral compound, researchers monitored the concentration of the active drug in a participant's blood serum over several hours following an oral dose.
At the start of the study (t=0t = 0t=0), the participant's baseline serum concentration of the compound was 12.5 mg/L12.5\text{ mg/L}12.5 mg/L due to a previous low-dose maintenance regime.
Figure 1 shows the recorded change in serum concentration relative to this baseline over a twelve-hour period.
Calculate the highest active serum concentration of the antiviral compound recorded during the clinical trial.
Determine the time taken for the serum concentration of the compound to decrease from its highest value back to its starting (baseline) value.