Pharmacokinetic studies on sulfamonomethoxine in rabbits

Abstract

The present study was performed to determine the pharmacokinetics of sulfamonomethoxine (20mg/kg) in 5 rabbits after its oral and intravenous administration. Blood samples were collected immediately before (time 0) and at 0.08, 0.25, 0.5, 1, 3, 5 and 8 hours post-dosing to evaluate the pharmacokinetics of sulfamonomethoxine. Plasma sulfamonomethoxine concentrations were quantified with HPLC-UV, and plasma drug concentration versus time data after IV was best fitted to the two-compartment model, characterized with the distribution phase (α) equaled to 2.05 h^-1 with a distribution half-life [t_0.5(α)] equaled to 0.61 h. The volume of distribution of (V¹_c) was 0.15 ml/kg., whereas the volume of distribution at a steady – state [V_dss] was 0.20 ml/kg, and the body clearance was 0.03 ml/ kg / h. After oral administration of SMM, plasma drug concentrations were best fitted to a two-compartment model, of which the mean half-life of absorption (t1/2_ab) and elimination (t1/2_β) were 0.02 and 1.99 h, respectively. The maximal absorption concentration (Cmax) was estimated as 114.06 μg/ml at 0.12 h, and the Area under the curve (AUC) was 340.42 μg/ml/h.