Comparative pharmacokinetics and bioavailability of two oral formulations of thiocolchicoside, a GABA-mimetic muscle relaxant drug, in normal volunteers
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The comparative pharmacokinetic and bioavailability profile of two different formulations (tablets and capsules) of thiocolchicoside was investigated in 8 healthy male volunteers after administration of single oral 8 mg doses. Plasma samples were assayed by a capillary gas chromatography — mass spectrometry (GC-MS) method following enzymatic hydrolysis of thiocolchicoside to its aglycone (3-demethylthiocolchicine) and no attempt was made to account for the possible occurrence of hydrolysis in vivo. Irrespective of the formulation used, the drug was rapidly absorbed from the gastrointestinal tract, peak levels of about 17 ng/ml being detected within 1 h in most subjects. Elimination was rapid, with mean MRT values of 5–6 h. All kinetic parameters showed considerable interindividual variability but none differed significantly between the two formulations. Relative to the tablet formulation, the oral bioavailability of the capsule formulation was 1.06 ± 0.39.
KeywordsThiocolchicoside 3-demethylthiocolchicine muscle relaxant pharmacokinetics bioavailability
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- 1.Janbroers J.M. (1987): Review of the toxicology, pharmaco-dynamics and pharmacokinetics of thiocolchicoside, a GABA-agonist muscle relaxant with antiinflammatory and analgesic actions. Acta Ther., 13, 221–250.Google Scholar
- 2.Capra C. (1970): Su alcune proprietá farmacologiche del tiocolchicoside. Fitoterapia, 41, 19–33.Google Scholar
- 4.Reynolds J.E.F. (ed.) (1993): Martindale — The Extra Pharmacopoeia. XXX Edn. Pharmaceutical Press, London, pp. 1210–1211.Google Scholar
- 5.Repertorio Farmaceutico Italiano. (1992): CEDOF Ed., Milan, pp. 1031–1032.Google Scholar
- 7.Capra C. (1967): Attivita’ antinfiammatoria del tiocolchicoside. Fitoterapia, 38, 16–21.Google Scholar
- 8.Capra C. (1967): Attivita’ analgesica del tiocolchicoside. Fitoterapia, 38, 66–71.Google Scholar
- 10.Griffini A., Martinelli E.M., Pifferi G. (1988): Quantitation of thiocolchicoside in rat plasma and urine by capillary gas chromatography and selected ion monitoring. 11th International Mass Spectrometry Conference, Bordeaux, 29 August–2 September, FRA 19.Google Scholar
- 11.Sherman J.M., Boudet R., Pontikis R., Nam N.-H., Fournier E. (1980): A sensitive radioimmunoassay for colchicine. J. Pharm. Pharmacol., 32, 800–802.Google Scholar