Pharmacokinetics of Three Sulfa-Drugs in the Fenneropenaeus chinensis

Abstract:

To better understand the use of sulfa drugs in aquaculture, especially in the culture of Fenneropenaeus chinensis, we studied the pharmacokinetics of three sulfa drugs in F chinensis using the high performance liquid chromatography (HPLC). The three selected sulfa drugs were sulfadimidine (SM2), sulfamethoxydiazine (SMD) and sulfadiazine (SD). The water temperature for the experiment was (24.6±2.4)℃. Healthy shrimp received oral administration of the drugs at a dose of 100 mg/kg. The results showed that the hemolymph concentration-time course of SM2, SMD and SD conformed to a two-compartment open model with the first order absorption after oral administration. Major pharmacokinetic parameters such as T1/2β, AUC, Vd, CL, Tmax and Cmax were 25.812 h, 34.066 mg/L•h, 94.553 L/kg, 2.608 L/h•kg, 2 h, 1.07 mg/L respectively for SM2, and 46.446 h, 45.39 mg/L•h, 97.207 L/kg, 1.504 L/h•kg, 1 h, 1.17 mg/L for SD, and 66.296 h, 65.917 mg/L•h, 40.015 L/kg, 0.763 L/h•kg, 2 h, 2.00 mg/L for SMD. These suggested that SMD was more widely distributed and absorbed than SM2 and SD in F. chinensis. The elimination half-life showed the order of SM2SD>SM2. As for the drug clearance rate, SMD had the fastest rate and SM2 had the slowest rate. Therefore in 72 hours after the oral administration, SMD had the most residues and the SM2 had the least residues in F. chinensis. In another word, SMD had the longest-lasting pesticide effect. Taking no account of other factors such as the cost and side effects, SMD could be the most suitable sulfa drug according to its pharmacokinetic characteristics. The comparison of the elimination half-life showed that SMD had the most enduring efficacy.