A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed which can separate and accurately quantitate paracetamol, dantrolene, cetirizine and pseudoephedrine. The method was successfully validated for the purpose of conducting stability studies of the four analytes in quality control (QC) laboratories. The stability-indicating capability of the method was demonstrated by adequate separation of these four analytes from all the degradant peaks. A gradient mobile phase system consisting of (A) 50 mmol L−1 sodium dihydrogen phosphate, 5 mmol L−1 heptane sulfonic acid sodium salt, pH 4.2 and (B) acetonitrile was used with Discovery reversed-phase HS C18 analytical column (250 mm × 4.6 mm i.d., 5 μm particle size). Quantitation was achieved with UV detection at 214 nm, based on peak area.
The proposed method was validated and successfully applied for the analysis of pharmaceutical formulations and laboratory-prepared mixtures containing the two multicomponent combinations.