Speciation of Antimony in Injectable Leishmanicidal Drugs by Lowering Citric Acid Concentration Used in Hydride Generation Atomic Absorption Spectrometry Analysis

Henrique Fabrino,Cynthia Demicheli,Frédéric Frezard,Letícia Costa

doi:10.21577/0103-5053.20200148

Henrique Fabrino, Cynthia Demicheli + Show 2 more

Open Access

https://doi.org/10.21577/0103-5053.20200148

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Abstract

This study proposes a procedure for speciation of antimony by hydride generation atomic absorption spectrometry in pentavalent antimony drugs. The SbIII content was determined by selective generation of SbH3 in medium with higher SbV concentration using 4 to 20-fold lower citric acid solutions than recommended in the available literature. The multivariate optimization of the methods was performed through factorial design followed by a central composite design (CCD). The limit of detection (LOD) and limit of quantification (LOQ) were calculated at 0.15 and 0.05 µg L-1 and 0.48 and 0.17 µg L-1, for total Sb and SbIII, respectively. The relative standard deviation (RSD) values ranged from 3.1 to 19.6% and 9.1 to 20.1%, while recovery ranged from 95.6 to 102.3% and 89.1 to 108.1%, for total Sb and SbIII, respectively. This method was applied for the analysis of meglumine antimoniate samples. Total Sb and SbIII concentrations ranged from 79.2 to 101.1 mg mL-1 and 0.08 to 0.41 mg mL-1, respectively.

Highlights

In the group of neglected infectious diseases, leishmaniasis presents itself as a major challenge, accounting for a yearly estimated 700,000-1,000,000 new cases and 26,000-65,000 deaths in the world.[1]
A 24 full factorial design with center point (CP) were evaluated: KI concentration [1.0(-); 5.5(0) and 10.0(+), in percentage (m v-1)]; NaBH4 concentration [0.6(-); 1.3(0) and 2.0(+), in percentage (m v-1)]; HCl concentration used in the acid channel [5.0(-);7.5(0) and 10.0(+), mol L-1], and the contact time of the analyte with the working solution (0(-); 60(0) and 120(+), s)
A matrix experiments of central composite design (CCD) (Table 1) was performed to evaluate the previously selected significant factors (HCl concentration was set at 5.0 mol L-1)

Summary

Introduction

In the group of neglected infectious diseases, leishmaniasis presents itself as a major challenge, accounting for a yearly estimated 700,000-1,000,000 new cases and 26,000-65,000 deaths in the world.[1] It is caused by leishmania protozoa, transmitted by the bite of infected female phlebotomine sandflies, and largely manifested as cutaneous (CL), mucocutaneous (MCL) and visceral (VL) leishmaniasis. The first successful Brazilian treatment for cutaneous leishmaniasis was reported by Gaspar Vianna.[2,3,4,5,6] His treatment employed intravenous injections of trivalent Sb,[2,3,4,5,6] which were substituted a few years later by less toxic pentavalent antimony complexes as stibamine urea, the first of several safer pentavalent antimonials which remained the basis for all leishmaniasis treatments.[4,5] Two of these complexes, the antimony sodium gluconate and meglumine

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