Dose dependent disposition of sulphadimidine and of its N₄‐acetyl and hydroxy metabolites in plasma and milk of dairy cows

Abstract

(1985) Dose dependent disposition of sulphadimidine and of its N 4 -acetyl and hydroxy metabolites in plasma and milk of dairy cows, Veterinary Quarterly, 7:3, 177-186, DOI: 10.1080/01652176.1985 SUMMARY The disposition of sulphadimidine (SDM) and of its N 4-acetyl (N4-SDM) and two hydroxy metabolites, 6-hydroxymethyl-(SCH,OH) and 5-hydroxyasulphadimidine (SOH), was studied in plasma and milk of dairy cows following intramuscular or intravenous administration of sulphadimididine-33.3% at doses of 10, 45, 50, and 100 mg/kg. The main metabolite in plasma as well as in milk was SCH,OH. The metabolite percentages, the final plasma elimination half-lives, and the time of peak SDM concentrations in milk are presented for different dosages. The concentrations of SDM and its metabolites in milk ran parallel to those in plasma beyond 4 hours p.i. The metabolite concentrations in plasma and milk were lower than those of the parent SDM. Sulphate and glucuronide metabolites could not be detected in milk. At high doses (45 mg/kg or more) and SDM plasma concentrations exceeding 20 pg/ml, a capacity limited metabolism of SDM to SCH2OH was noticed, viz, a steady state concentration of SCH,OH and a biphasic elimination pattern for SDM and SCH,OH in plasma and milk. The mean ultrafiltrate ratios of the milk to plasma concentrations with respect to SDM, SCH,OH, SOH, and 114-SDM were: 0.69, 0.22, 020, and 0.63, respectively. The total amount of SDM and its metabolites recovered from the milk after milking twice daily over the whole experimental time was less than 2% of the applied dose. A bioassay method allowed of detecting qualitatively SDM concentrations exceeding 0.2 pg/ml in plasma or milk. Withholding times for edible tissues and milk are suggested.

Residues of sulphadimidine and its metabolites in eggs following oral sulphadimidine medication of hens

“…In poultry farming, sulphonamides are widely used for the treatment of coccidiosis and infectious coryza. Recently, with the employing of specific HPLC methods, it has been shown that various avian and mammalian species are able to metabolise sulphadimidine extensively by acetylation and hydroxylation (13,14,22). This study is an extension of a former one (15) and presents data on the persistence of sulphadimidine (SDM) and its hydroxy and Kracetyl metabolites in eggs of laying hens following oral SDM medication.…”

“…Based on the passive diffusion concept (4, 18), a dynamic equilibrium is established between the SDM concentration in plasma and in the egg white present in the magnum. SDM, N4-SDM and methylhydroxy metabolites diffuse easily across membranes (13). Therefore their concentrations in the egg white must be a reflection of those in plasma (Fig.…”

“…Analysis of plasma samples for SDM and metabolites was performed by HPLC procedures as described previously (13). As the mobile phase a mixture of methanol, acetonitrile, 0.02 M sodium acetate, 0.2 M acetic acid and distilled water (12.4 : 2.8 : 35.7 : 6.9 : 42.3) was used at a pH of 4.8.…”

Pharmacokinetics, renal clearance and metabolism of ciprofloxacin following intravenous and oral administration to calves and pigs

“…HPLC analysis HPLC equipment as described elsewhere was used (11,16). The column was a Spherisorb 5 ODS (250x4.6 mm I.D.…”

Some pharmacokinetic data about furaltadone and nitrofurazone administered orally to preruminant calves

“…The H PLC equipment as described elsewhere was used (7). The column was a Zorba x CN 4.6x250 mm (Du Pont Ltd., France) (9); the mobile phase was a mixture of acetonitrile, 0.02 M sodium acetate, 0.2 M acetic acid (v/v 30:60.5:9.5), all analytically pure, the final pH being 5.0.…”