Pharmacokinetics of sarafloxacin hydrochloride in the pacific white shrimp, Litopenaeus vannamei, following multiple-dose oral administration

The present study was designed to explore the pharmacokinetics and tissue distribution levels of sarafloxacin hydrochloride in the pacific white shrimp, Litopenaeus vannamei, after oral administration of multiple doses (30 mg/kg, twice a day for 5 days). Eighteen shrimps per sampling point were examined during and after treatment. Sarafloxacin hydrochloride concentrations in the hemolymph, hepatopancreas, and muscle of the pacific white shrimp were determined using HPLC. Pharmacokinetic parameters were analyzed based on the statistical moment theory. The results showed rapid absorption of sarafloxacin hydrochloride in hepatopancreas, hemolymph, and muscles (Tₘₐₓ = 2 h) after oral administration. Sarafloxacin hydrochloride peak concentration in the hemolymph, hepatopancreas, and muscle were 12.236 mg/L, 376.939 mg/kg, and 6.17 mg/kg, respectively. Tissue distribution (AUC)₀₋∞ followed the order hepatopancreas > hemolymph > muscle, indicating the hepatopancreas was the main organ involved in sarafloxacin hydrochloride metabolism in the pacific white shrimp. After multiple-dose oral administration, some accumulation occurred in the hepatopancreas, while in the hemolymph and muscle, sarafloxacin hydrochloride reached a steady state following multiple-dose administration. The t₁/₂z values of sarafloxacin hydrochloride in hemolymph, hepatopancreas, and muscle were 27.403 h, 20.456 h, and16.852 h, respectively. The values of AUCₛₛ, Cₜᵣₒᵤgₕ, and Cₐᵥ were graded as hepatopancreas > hemolymph > muscle, showing hepatopancreas played an important role in drug metabolism and elimination in shrimp. In addition, the withdrawal period of 4 days after the last oral medication was recommended based on the calculated value of WT1.4 software and the actual detected value of sarafloxacin hydrochloride in the muscle of the pacific white shrimp. When Vibrio parahaemolyticus was used as an indicator, the ratio of AUC₀₋ₜ/MIC₉₀ and Cₘₐₓ/MIC₉₀ were 101.15 and 12.24, respectively.