FIG. 3.

PK profiles of EP40111 and enfuvirtide in rats. Both compounds were administered intravenously at 4 mg/kg (i.e., 0.56 μmol/kg of EP40111 and 0.89 μmol/kg of enfuvirtide) to rats, and blood was sampled at the indicated times. The corresponding concentrations of EP40111 and enfuvirtide were evaluated by LC-MS/MS by using the ¹³C- and ¹⁵N-labeled enfuvirtide peptide as an internal standard. These results represent the means and standard deviations of two independent experiments. The enfuvirtide plasma concentration at 48 h was below the detection limit, so the point could not be indicated on this semilogarithmic graph.