New insights into the chemical structure and composition of the pentavalent antimonial drugs, meglumine antimonate and sodium stibogluconate

Quantitative HPLC-ICP-MS analysis of antimonyredox speciation in complex sample matrices: new insights into the Sb-chemistry causing poor chromatographic recoveries

“…As a negative control, a solution of KSb(OH) 6 (1.00 mM) was ultrafiltrated with no decrease in Sb concentration. These findings are in agreement with previous reports of Sb-containing polymers in Pentostam 19,20 and suggest that polymers also have been formed in the ascorbic acid-Sb(V) mixture. (The fraction of Sb in the Sb-ascorbic acid mixture unrecoverable from the HPLC column when not treated with acid is much more than 8%, showing that the unrecoverable Sb species also include some that are less than 3 kDa molecular weight.…”

“…19 Likewise, the drug meglumine antimonate is oligomeric due to chelation by vicinal hydroxy functions. 20 Several types of organic Sb(V) polymers are described where Sb is bound via oxygen atoms in a non-chelate fashion, e.g. as ether or ester bonds.…”

Amphiphilic Antimony(V) Complexes for Oral Treatment of Visceral Leishmaniasis

“…A previous pharmacokinetic study of meglumine antimoniate with dogs indicated an oral bioavailability of about 10% (15). Such a low bioavailability can be attributed to the highly hydrophilic character of meglumine antimoniate and also to its tendency to polymerize in concentrated aqueous solutions (22). As an attempt to improve the oral bioavailability of pentavalent antimony, a strategy based on the formation of amphiphilic antimony(V) complex was investigated.…”

“…The kinetic stability of SbL8 nanoassemblies indicates that they do not readily dissociate following dilution in biological fluids. This property may be attributed to the low rate of dissociation of the Sb(V)OO bond (22,25). This property may be explored in the future through the use of these nanostructures as carrier systems of other lipophilic drugs.…”

Anticancer Activity of Molecular Compounds of Arsenic, Antimony and Bismuth

“…The two most prominent antimony compounds used in the treatment of cutaneous and visceral leishmaniasis are sodium stibogluconate (XIX, Pentostam) and meglumine antimonate (XX, Glucantime): their molecular compositions let alone precise molecular structures remain uncertain [55]. While each of these drugs features an antimony(V) centre, it is likely that these are reduced to antimony(III) in vivo [51].…”