Insights for applying erythrosine B as a green fluorescence probe for estimation of anticancer tamoxifen and its analog; clomiphene in nanogram concentration

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Dec 15:263:120156. doi: 10.1016/j.saa.2021.120156. Epub 2021 Jul 12.

Abstract

The growth of tumor tissue is extremely pervasive among post-menopausal women. Commonly, from the clinical application, adjuvant selective estrogen receptor modulators such as tamoxifen are prescribed for prohibiting metastatic breast cancer, while its analog, clomiphene, is used to treat infertility in women. Lately, the significance of green chemistry on our environment was through reducing the influence of hazardous chemicals. Consequently, efforts were screened to perform a fast and simple eco-friendly green method for the determination of two aromatase inhibitors. In this study, a sensitive green spectrofluorimetric approach was developed to detect and characterize tamoxifen citrate (TAM) and clomiphene citrate (CLO) via complex formation with erythrosine B. The reaction between erythrosine B dye (EB) and the two aromatase inhibitors results in quenching the fluorescence activity of the dye by the formation of ion-pair in Britton-Robinson buffer (BRB) solution (pH 4.3) at 554 nm (λex = 527 nm). The approach outcome confirmed that the solvent's inherent nature has a critical impact on the approachs' sensitivity and reproducibility. An approved linear correlation was achieved between the reduction in the emission value of EB's fluorescence and the concentration in the ranges of 40.0-600.0 ng/mL for both TAM and CLO with mean % recoveries 100.20 ± 0.93 and 100.07 ± 1.09, respectively. The approach was validated regarding ICH protocols, and the outcomes were acceptable. The changes in Gibb's free energy (ΔG°) by the obtained ion-pair between EB and TAM or CLO were -36.65 or -37.03 kJ mol-1, respectively, which indicates the reaction feasibility at ambient temperature. Commercial dosage forms for TAM and CLO were simply analyzed, and good recoveries were achieved within the range. The National Environmental Methods Index, Analytical Eco-Scale, and Green Analytical Procedure Index applications to our illustrated approach present additional eligibility to this study.

Keywords: Clomiphene; Erythrosine B; Gibb’s free energy; Green chemistry; Spectrofluorimetric; Tamoxifen.

MeSH terms

  • Clomiphene*
  • Erythrosine*
  • Female
  • Fluorescent Dyes
  • Humans
  • Reproducibility of Results
  • Tamoxifen

Substances

  • Fluorescent Dyes
  • Tamoxifen
  • Clomiphene
  • Erythrosine