Iwao Maeda

Simultaneous determination of sulphamonomethoxine and its N4-acetyl metabolite in blood serum by high-performance liquid chromatography with direct injection

A high-performance liquid chromatographic method with direct injection has been developed for the simultaneous determination of sulphamonomethoxine and its N4-acetyl metabolite in serum of animals and fish. A HISEP shielded hydrophobic-phase column (15 cm x 4.6 mm I.D.), a mobile phase of 0.05 M citric acid-0.2 M disodium hydrogenphosphate-acetonitrile (70:15:15, v/v), and ultraviolet detection at 265 nm were used. The standard calibration curves in serum of chicken, pig, cattle, rainbow trout and yellowtail were linear over the range 0.5-20 micrograms/ml. The recoveries of sulphamonomethoxine and its N4-acetyl metabolite from all serum samples determined at different concentrations (0.5, 2.0 and 10.0 micrograms/ml) were 93-103% and 90-103%, respectively. The lowest measurable sulphamonomethoxine and N4-acetyl metabolite concentrations were 0.04 and 0.1 microgram/ml, respectively, for all serum samples.

Pharmacokinetics and metabolism of sulphamonomethoxine in rainbow trout (Oncorhynchus mykiss) and yellowtail (Seriola quinqueradiata) following bolus intravascular administration

Abstract The present study examined the pharmacokinetics and metabolism of sulphamonomethoxine (SMM) in rainbow trout ( Oncorhynchus mykiss ) and yellowtail ( Seriola quinqueradiata ) after intravascular administration (100 mg kg −1 body weight). Rainbow trout and yellowtail were kept in tanks with running water at 15.0 ± 0.3 °C and running sea water at 21.3 ± 0.2 °C, respectively. Serum concentrations of SMM were determined using high performance liquid chromatography with direct injection. Serum concentrations of SMM in rainbow trout and yellowtail were best described by a two-compartment model. The calculated half-lives for the distribution phase and the elimination phase were 0.43 h and 30.9 h for rainbow trout, and 0.53 h and 5.8 h for yellowtail, respectively. The apparent volume of distribution ( V d ) was larger in rainbow trout ( V d = 0.83 1 kg −1 ) than in yellowtail ( V d = 0.56 1 kg −1 ). Total body clearance was calculated as 18.5 ml kg −1 h −1 in rainbow trout and 66.7 ml kg −1 h −1 in yellowtail. The behaviour of N 4 -acetyl metabolite, N 4 -acetylsulphamonomethoxine (AcSMM), in rainbow trout and yellowtail could be explained well by a one-compartment model. The formation rate constant of the metabolite and the elimination half-lives were 0.0694 h −1 and 15.4 h for rainbow trout, and 0.1896 h −1 and 8.1 h for yellowtail, respectively. Acetylation in rainbow trout and yellowtail was calculated to be 23% and 64%, respectively. The serum protein bindings in vivo of SMM and AcSMM were determined to be 6.4 ± 2.3% and 9.5 ± 3.6% for rainbow trout, and 5.8 ± 1.7% and 6.3 ± 2.3% for yellowtail, respectively.

Modification of Universal Rheometer to a Viscograph

デンプンの粘度の測定には,でき上ったデンプンノリの粘度を測定するレオメーターとノリ化の過程の粘度を測定するビスコグラフがある.この両機械の粘度測定機構は同じであることから,レオメーターに付属品をつけて,ビスコグラフとしても用いられるようにした. この改造ビスコグラフによる粘度測定の結果,他のビスコグラフとほぼ同様な精度で,しかも数gの少量の試料で各種デンプンの粘度を比較しうることがわかった. また同じ種類のデンプンの粘度を比較する場合には, バレイショ4%,カンショ5%,サトイモ7%,クズ5%,トウモロコシ7%,コムギ8%,ウルチマイ6%,モチマイ5%程度が適当の濃度である.