Epimerization kinetics of moxalactam in frozen urine and plasma samples.
Pharm Res
; 7(4): 364-9, 1990 Apr.
Article
en En
| MEDLINE
| ID: mdl-2362909
ABSTRACT
The epimerization of moxalactam (LMOX) in frozen urine and plasma samples was studied during long-term storage. The R/S ratio at equilibrium [(R/S)eq] at -10 degrees C was similar in urine and in rat and human plasma ultrafiltrate but differed from that in water. The (R/S)eq values in human plasma and its ultrafiltrate differed slightly, while they were the same in rat plasma and in its ultrafiltrate. The difference for the human plasma and ultrafiltrate may result from differences in plasma protein binding between R- and S-epimers in the liquid region of the frozen plasma. The change of R/S ratio in frozen human plasma continued below the collapse temperature of LMOX aqueous solution, where the liquid region appeared still to exist as determined by NMR measurement. Consequently, the biological LMOX samples should be preserved at or below -70 degrees C to prevent changes in the R/S ratio.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Moxalactam
Límite:
Animals
/
Humans
/
Male
Idioma:
En
Revista:
Pharm Res
Año:
1990
Tipo del documento:
Article
País de afiliación:
Japón