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Pharmacokinetics of reboxetine enantiomers in the dog
Author(s) -
Frigerio E.,
Benecchi A.,
Brianceschi G.,
Pellizzoni C.,
Poggesi I.,
Benedetti M. Strolin,
Dostert P.
Publication year - 1997
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/(sici)1520-636x(1997)9:3<303::aid-chir17>3.0.co;2-r
Subject(s) - chemistry , reboxetine , enantiomer , pharmacokinetics , pharmacology , stereochemistry , biochemistry , receptor , medicine , reuptake inhibitor , serotonin
Reboxetine, (RS)‐2‐[(RS)‐α‐(2‐ethoxyphenoxy)benzyl]morpholine methanesulphonate, is a racemic compound and consists of a mixture of the (R,R)‐ and (S,S)‐enantiomers. The pharmacokinetics of reboxetine enantiomers were determined in a crossover study in three male beagle dogs. Each animal received the following oral treatments, separated by 1‐week washout period: 10 mg/kg reboxetine, 5 mg/kg (R,R)‐ and 5 mg/kg (S,S)‐. Plasma and urinary levels of the reboxetine enantiomers were monitored up to 48 h post‐dosing using an enantiospecific HPLC method with fluorimetric detection (LOQ: 1.1 ng/ml in plasma and 5 ng/ml in urine for each enantiomer). After reboxetine administration mean t max was about 1 h for both enantiomers. C max and AUC were about 1.5 times higher for the (R,R)‐ than for the (S,S)‐enantiomer, mean values ± SD being 704 ± 330 and 427 ± 175 ng/ml for C max and 2,876 ± 1,354 and 1,998 ± 848 ng.h/ml for AUC, respectively. No differences between the (R,R)‐ and (S,S)‐enantiomers were observed in t½ (3.9 h). Total recovery of the two enantiomers in urine was similar, the Ae (0–48 h) being 1.3 ± 0.7 and 1.1 ± 0.7% of the enantiomer dose for the (R,R)‐ and the (S,S)‐enantiomers, respectively. No marked differences in the main plasma pharmacokinetic parameters were found for either enantiomer on administration of the single enantiomers or reboxetine. No chiral inversion was observed after administration of the separate enantiomers, as already observed in humans. Chirality 9:303–306, 1997. © 1997 Wiley‐Liss, Inc.