Separation and Determination of Paracetamol and Codeine Phosphate in Pharmaceutical Preparation by using High Performance Liquid Chromatography

Accurate and precise high performance liquid chromatography (HPLC) method was developed for the determination of Paracetamol (Par) and Codeine phosphate (Cod) in pharmaceutical formulations. The chromatographic separation was achieved with acetonitrile: phosphoric acid (pH = 2.8) in ratio of 35:65 (v/v) as mobile phase on a Shim-pack clc-C₈ column (25 cm x 4.6 mm i.d., 5 μm) with UV detection at 212 nm, pump flow rate 1.0 mL/min and sample injection volume 20 μL. The analysis time was < 8 min. The method was validated with respect to linearity, precision, accuracy, selectivity and specificity. The calibration curves showed good linearity over the concentration range of (3 - 600) μg/mL and (1 - 800) μg/mL for (Par) and (Cod) respectively in presence of methyl paraben (MP) as internal standard. The proposed method was successfully applied to analysis individual or mixture of (Par) and (Cod) in Syrian trademark drugs. All studied samples showed that the drug levels were conformed to united state pharmacopeia (USP) legislation. Finally, the described chromatographic procedure here is accurate, precise, selective and suitable for routine quality control analysis and stability tests.