Disposition of antimony and aminosidine combination after multiple subcutaneous injections in dogs

The disposition of a combination of antimony (Sb-v) (12.8 mg/kg) and aminos idine (AM) (10 mg/kg) in 10 healthy Beagle dogs after multiple subcutaneous injections is described. Sb-v plasma concentrations were determined by ato mic absorption spectrometry, and AM by ion-pair liquid chromatography, usin g a fluorimetric detector. Sb-v reached C-max at 60 min, and for about 1 h plasma levels were homogeneously stabilized between 10.78 and 11.76 mu g/mL ; by 12h, Sb-v plasma concentrations were close to the detection limit (0.3 mu g/mL). AM C-max values were recorded after 1 h (30.6 +/- 3.11 mu g/mL, mean +/- SD), and plasma levels reached values close to the detection limit (0.15 mu g/mL) between 7 and 8 h after injection. Sb-v kinetic parameters did not appear modified by the presence of AM. Moreover, repeated injection s of the combination did not modify the kinetic behaviour of the two drugs and did not alter the renal function of the animals. The superimposition an alysis of the Sb-v data suggests that a twice daily injection of the metal at a dose of 12.8 mg/kg would be sufficient to maintain inhibitory Sb-v con centrations similar to those recorded in humans.