In vitro and in vivo methods to measure the ceftriaxone distribution into the rat tail intervertebral disc.
To characterize the pathway of ceftriaxone penetration into intervertebral discs, rat-tail discs were collected and immersed in a ceftriaxone solution for an in vitro study. For this in vivo experiment, plasma and tail discs were collected 30 min after ceftriaxone administration (463.2 mg/kg, equal to 500 mg/kg disodium salt, iv). The ceftriaxone levels in the plasma and discs were determined with HPLC by a reversed-phase C18 column and a mobile phase of methanol and a 10 mM K(2)HPO(4) solution (pH 6.7) (21:79, v/v). The results indicate that ceftriaxone was undetectable by the in vitro model. The concentrations of ceftriaxone in plasma and in intervertebral discs were 147.4 ± 21.2 and 4.0 ± 1.7 µg/mL (as disodium salt), respectively. Our results suggest that a sufficient blood supply is required for the passive diffusion of ceftriaxone into intervertebral discs. The concentration ratio of ceftriaxone in intervertebral disc-to-plasma was about 2.7% at 30 min after ceftriaxone disodium administration (500 mg/kg, iv).
Lin
Chia-Chun
CC
Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan.
Wu
Yu-Tse
YT
Yen
Jiin-Cherng
JC
Chiang
Chang-Jung
CJ
Tsuang
Yang-Hwei
YH
Tsai
Tung-Hu
TH
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002443:Ceftriaxone / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D004058:Diffusion / Q000187:drug effects; D066298:In Vitro Techniques; D007403:Intervertebral Disc / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013623:Tail
D000900:Anti-Bacterial Agents; D002443:Ceftriaxone