[Serum protein binding of T-3761].
We investigated the extent of the binding of T-3761 to serum protein and obtained the following results. 1. The binding rates of T-3761 to serum protein from various animals and human were 16.9-27.7%, and a little higher than those of ciprofloxacin and ofloxacin. 2. The binding rates of T-3761 to human serum protein were 19.1-23.8% at concentrations of 0.25-20 micrograms/ml. 3. The binding rates of T-3761 lowered as the decrease of protein concentration. 4. The binding rates of T-3761 (2 micrograms/ml) to human serum protein were 12.4, 21.3 and 32.1% at pH 7.0, 7.4 and 8.0, respectively, showing the effect of the pH. 5. The binding of T-3761 to human serum protein was reversible. 6. In vivo binding rates of T-3761 in rabbits after a single oral administration of 20 mg/kg were 26.1-33.2%, which were similar to those obtained in vitro.
Kitayama
R
R
Research Laboratories, Toyama Chemical Co., Ltd.
Hayashi
T
T
Minami
S
S
Watanabe
Y
Y
Narita
H
H
D000818:Animals; D000890:Anti-Infective Agents; D001798:Blood Proteins / Q000378:metabolism*; D004285:Dogs; D005260:Female; D024841:Fluoroquinolones; D006863:Hydrogen-Ion Concentration; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010078:Oxazines / Q000378:metabolism*; D011485:Protein Binding; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar
D000890:Anti-Infective Agents; D001798:Blood Proteins; D024841:Fluoroquinolones; D010078:Oxazines; C078052:pazufloxacin