RP-HPLC method development, validation and pharmacokinetic applicability in preclinical evaluation of rhein treated with novel diacerein eutectics.

The current study represents a bioanalytical method for the estimation of rhein (Rh, an active metabolite of diacerein, DIA) in rats treated with novel DIA eutectics to investigate the pharmacokinetics of DIA. A simple protein precipitation technique was used to extract Rh and the internal standard (IS), p-aminobenzoic acid, injected into a Phenomenex Gemini C column. The separation was achieved by a gradient elution comprising ammonium acetate (10 mm; pH 3.