Adsorptive stripping voltammetry determination of the hormone therapy raloxifene HCl in formulation and human serum

Abstract

Raloxifene HCl (RLX) was found to strongly adsorb onto surface of the mercury electrode in a monolayer surface coverage of 5.724 × 10 -10 mol cm-2. Two precise, rapid and extraction-free linear sweep and square wave adsorptive cathodic stripping voltammetry (LS-AdCSV and SW-AdCSV, respectively) methods are described for trace quantitation of RLX in bulk form, commercial formulation and human serum. Limits of quantification (LOQ) of 2.0 × 10-9 and 5.0 × 10-11 mol L -1 RLX in bulk form and 4.0 × 10-9 and 1.0 × 10-10 mol L-1 RLX in spiked human serum were achieved by the described LS-AdCSV and SW-AdCSV methods, respectively. Insignificant interferences from some common excipients, metal ions and co-administrated drugs were obtained. LOQ achieved by the methods are low as well as they offer good possibilities for determination of drug in low-dosage pharmaceutical preparations. However, the SW-AdCSV method described is sensitive enough to assay the drug also in human serum. © 2012 Sociedade Brasileira de Química.