• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.7-12
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• 2006

We have studied pharmacokinetics of a new anti-human immunodeficiency virus (HIV) agent VP-0501 and its amino acid prodrug VP-0501AL which is designed to improve oral bioavailability. After oral administration at 100 mg/kg dose in rats (n = 4), VP-0501 was not detectable in plasma (<50 ng/ml), while after the administration of VP-0501AL, VP-0501 was quantitatively detected, at least for 8 hrs, with Cmax of ca. $2.5{\mu}g/ml$ and AUC of $8hr^{\ast}{\mu}g/ml$. When VP-0501 was intravenously administered at 50mg/kg, this compound appeared at a marginal level in plasma with AUC of $2hr^{\ast}{\mu}g/ml$, $t_{1/2}$ of 2 hr, $C_0$ of $0.7{\mu}g/ml$, and MRT of 3 hr. On the other hand, with intravenous VP-0501AL at the same dose, both the prodrug VP-0501AL and its metabolite VP-0501 appeared comparatively at higher level in the plasma: pharmacokinetic parameters of VP-0501AL including $Vd_{\beta}$, AUC, $t_{1/2,{\beta}}$, $C_0$, $CL_{tot}$, and MRT were ca. 2 L/kg, $70hr^{\ast}{\mu}g/ml$, 2 hr, $180{\mu}g/ml$, 0.7 L/hr/kg, and 1 hr, respectively. These results demonstrate that attachment of amino acid alanine to VP-0501 is an effective approach for improvement of its oral bioavailability. Therefore, VP-0501AL is expected to become a new highly bioavailable and potent anti-AIDS drug candidate/lead compound.