Pharmacokinetics of oxolinic acid in black tiger shrimp, Penaeus monodon Fabricius, and the effect of cooking on residues

Abstract

AbstractThis study examined the pharmacokinetics andbioavailability of oxolinic acid (OA) in black tigershrimpPenaeus monodon Fabricius,inbrackishwater(salinity 10gL 1 )at28^291C, after intra-sinus (10mgkg 1 ) and oral (50mgkg ) administration andalso investigated the net changes of OA residuesin the shrimp after cooking (boiling, baking andfrying).The haemolymph concentrations of OAafterintra-sinusdosingwerebestdescribedbyatwo-com-partment open model.The distribution and elimina-tion half-lives were 0.84 and17.7h respectively. Theapparent volume of distributionata steadystate andthe total body clearance were estimated to be2061mL kg 1 and 90.1mLkg h respectively.Thebioavailabilityof OAafteranoraladministrationwas 7.9%. The peak haemolymph concentration,the time to peak haemolymph concentration andthe elimination half-life after oral administrationwere 4.20mgmL 1 ,4h and19.8h respectively. Oxo-linic acid muscle and shell levels increased to amaximum (muscle1.76 mgg 1 and shell 8.17mgg )at 4h post administration and then decreased withthe elimination half-life value of 20.2 and 21.9hrespectively. Residual OA in muscle and shell wasreduced by 20^30% by each cooking procedureexamined.Keywords: pharmacokinetics, oxolinicacid, Pena-eus monodon, black tiger shrimp, bioavailability,cookingIntroductionIn Southeast Asia, intensive shrimp farming has de-veloped rapidly inthelast decade. Blacktiger shrimpPenaeusmonodon Fabriciusisaneconomicallyimpor-tant export inThailand, and the greater part of pro-ductionis consumedbytheUSAandJapan.Recently,diseases caused byVibrio bacteria are a serious pro-blem causing economic damage to theThai shrimpindustry.Toreduce diseaseproblems, awide range ofchemotherapeutics has been used. The use of che-motherapeuticdrugs in shrimpfarmingcan haveanimpact on the aquatic environment and potentiallycause health risks because of drug residues in theshrimpsoldforconsumption.Oneofthemajorenvir-onmental eiects by using antibacterial agents isdevelopment of bacterial resistance. Therefore, theproperuseofdrugsisstronglyrecommendedtoavoidsuch problems. Knowledge of pharmacokinetics andresidue depletion is important to minimize humanrisk associated with drug residues and the environ-mental impactof thedrugs.Currently,oxolinicacid(OA)isthemostcommonlyused agent in Thai shrimp culture farms. The phar-macokineticpro¢leofOAhaspreviouslybeenstudiedin rainbow trout Oncorhynchus mykiss (Walbaum)(Bj˛rklundBHustvedtSKlei-now, Jarboe, Shoemaker & Greenless 1994), Atlanticsalmon Salmo salar L. (Hustvedt, Salte & Vassvik1991;Rogstad,EllingsenSMartinsen& Horsberg1995; Samuelsen, Ervik, Pursell & Smith2000),channelcat¢shIctaluruspunctatusL.(Kleinow