New extraction procedures for isolation of famotidine from aqueous samples

Abstract

Liquid-liquid and solid-phase extraction procedures are proposed for famotidine isolation from aqueous samples. The isolation and spectrophotometric determination of famotidine is based on its complexation reaction with thymol blue. The composition of a complex between drug and reagent (1 : 1) was established. Dichloromethane and methanol were used as extraction solvents for LLE and SPE processes. Quantification of famotidine was done spectrophotometrically at 544 nm for dichloromethane or at 434 nm for methanolic extracts. The Beer law is obeyed in the famotidine concentration range 3 · 10−5 mol L−1–2.0 · 10−4 mol L−1 for LLE procedure and 2.0 · 10−6 mol L−1–8.0 · 10−5 mol L−1 for SPE.