Exploratory bioavailability and pharmacokinetic studies of sulphadimethoxine and ormetoprim in the penaeid shrimp, Penaeus vannamei

• Published in: Aquaculture Vol. 130; no. 2; pp. 113 - 128
• Main Authors: Park, Eric D., Lightner, Donald V., Milner, Nicholas, Mayersohn, Michael, Park, Douglas L., Gifford, James M., Bell, Thomas A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.02.1995; Elsevier Science; Elsevier Sequoia S.A
• Subjects: Animal aquaculture; Animal productions; Aquaculture; BIOAVAILABILITY; BIODISPONIBILIDAD; BIODISPONIBILITE; Biological and medical sciences; DRUGS; FARMACOLOGIA; Fundamental and applied biological sciences. Psychology; MEDICAMENT; MEDICAMENTOS; Ormetoprim; PENAEUS VANNAMEI; Pharmacokinetics; PHARMACOLOGIE; PHARMACOLOGY; Pisciculture; Shellfish; Sulphadimethoxine; Vertebrate aquaculture; Penaeus vannamei; Sulphadimethoxine; Pharmacokinetics; Ormetoprim; Sulfanilamide derivatives; Bioavailability; Macrura; Crustacea; Antiprotozoal agent; Arthropoda; Parasiticid; Antiinfectious; Decapoda; Invertebrata; Aquaculture
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/0044-8486(94)00217-C

The pharmacokinetics and bioavailability of sulphadimethoxine (SDM) and ormetoprim (OMP) were examined, following simultaneous administration in penaeid shrimp. The hemolymph concentration versus time data following intra-sinus injection for both SDM (42 mg/kg) and OMP (8.6 mg/kg) were well described by a multiexponential equation suggesting multicompartmental behavior. The SDM:OMP parameter estimates of systemic clearance, steady-state volume of distribution, and disposition half-life were 215:1765 ml/kg · h, 1319:34 382 ml/kg, and 9.0:17.8 h, respectively. Hemolymph protein binding of SDM and OMP was 5.2% and 12.1%, respectively. The bioavailabilities of SDM and OMP were 30% and 32%, respectively. Peak hemolymph concentration ( C max) and time of occurrence of that value ( T max) for SDM following a single oral dose (210 mg/kg) were 25.0 μg/ ml at 4 h, while the corresponding values for OMP were (dose, 42 mg/kg) 0.70 μg/ml at 4 h. The percent of the available oral dose 2 h post-administration for SDM:OMP in the hemolymph, muscle, and hepatopancreas were 5.0:0.6%, 7.8:3.4%, and 2.4:24.8%, respectively. Hemolymph and muscle tissue concentrations were below detectable limits after 48 h for SDM and 24 h for OMP. The SDM:OMP drug combination has good potential as a shrimp chemotherapeutant in that they were rapidly and moderately absorbed, have relatively short half-lives and low hemolymph protein binding which translates to the bulk of absorbed drugs being available for a therapeutic response.