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Pharmacokinetics of tiazofurin in dogs
Author(s) -
Obeng E. K.,
Vallner J. J.,
Cadwallader D. E.,
Tackett R. L.
Publication year - 1987
Publication title -
biopharmaceutics and drug disposition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 58
eISSN - 1099-081X
pISSN - 0142-2782
DOI - 10.1002/bdd.2510080204
Subject(s) - pharmacokinetics , oral administration , pharmacology , half life , volume of distribution , elimination rate constant , free fraction , chemistry , distribution (mathematics) , medicine , mathematical analysis , mathematics
The pharmacokinetics of total and free tiazofurin, an antineoplastic agent, was studied in healthy mongrel dogs following intravenous and oral administration of the drug. The free fraction of tiazofurin was obtained from plasma by an ultrafiltration technique using a micropartition system. Total and free tiazofurin levels were determined by a sensitive high performance liquid chromatographic method. The percentage of tiazofurin bound to plasma proteins remained constant at approximately 15 per cent following administration to healthy mongrel dogs. The mean pharmacokinetic parameters of elimination rate constant ( K ), effective half‐life ( t 1/2 ), mean residence time (MRT) and the time to reach peak plasma level ( t max —after oral administration) were 0.32 ± 0.04 h −1 , 2.24 ± 0.25 h, 3.23 ± 0.36 h, and 1.78 ± 0.50 h, respectively. The apparent volume of distribution at steady state was 0.98 ± 0.30 I kg −1 and the plasma clearance was 5.24 ± 2.39 ml min −1 kg −1 . About 90 per cent of tiazofurin was absorbed following oral administration. The pharmacokinetic parameters did not differ significantly between the total and free drug levels, indicating that the pharmacokinetics of total tiazofurin levels reflect those of the free tiazofurin in plasma.