Antimony oxidation states in antileishmanial drugs.
Chemical methods specific for the determination of the levels of trivalent antimony (Sb+3) and pentavalent antimony (Sb+5) were used to investigate proprietary formulas used to treat leishmaniasis. Trivalent antimony was determined by differential pulse polarography, whereas Sb+5 was determined by iodine titration. Proprietary formulas based on N-meglumine antimoniate (Glucantime) were analyzed in detail. The results showed Sb+3 in all ampules of Glucantime. In formulations said to contain either 85 or 100 mg of Sb+5/ml, we found both forms of antimony. The amount of Sb+3 ranged from 10.5 to 15.8% (10.06-18.96 mg of Sb/ml). These findings raise issues on product stability and standardization and may help to clarify resistance to antimonial drugs and the reducing effect of tissue on Sb+5.
Franco
M A
MA
Department of Chemistry, University of Brasilia, Brazil.
Barbosa
A C
AC
Rath
S
S
Dorea
J G
JG
D000965:Antimony / Q000032:analysis / Q000378:metabolism*; D000967:Antimony Sodium Gluconate / Q000737:chemistry* / Q000592:standards; D000981:Antiprotozoal Agents / Q000737:chemistry* / Q000592:standards; D004355:Drug Stability; D008536:Meglumine / Q000737:chemistry* / Q000592:standards; D000077485:Meglumine Antimoniate; D009942:Organometallic Compounds / Q000737:chemistry* / Q000592:standards; D010084:Oxidation-Reduction
D000981:Antiprotozoal Agents; D009942:Organometallic Compounds; D008536:Meglumine; D000077485:Meglumine Antimoniate; D000965:Antimony; D000967:Antimony Sodium Gluconate