Simultaneous determination of diclofenac sodium and paracetamol in a pharmaceutical preparation and in bulk drug powder by high-performance thin-layer chromatography

A normal-phase high-performance thin-layer chromatographic (HPTLC) method has been established for simultaneous quantitative determination of diclofenac sodium and paracetamol in a pharmaceutical formulation and in bulk drug powder. The analysis was performed on silica gel 60F(254) HPTLC plates with toluene-ethyl acetate-methanol-formic acid, 5.0 + 4.0 + 1.0 + 0.01 (v/v), as mobile phase. Detection and quantitation were performed densitometrically at lambda = 260 nm. Aceclofenac was used as the internal standard. Responses of diclofenac sodium standard and paracetamol stan(lard were linear functions of concentration in the ranges 30-800 ng mu L-1 and from 300-2000 ng mu L-1, respectively. The method was validated to determine its accuracy and precision. Accuracy was checked by conducting recovery studies; average recovery from the pharmacentical preparation was 99.57% for diclofenac sodium and 100.51% for paracetamol. This HPTLC method developed for simultaneous quantitative determination of diclofenac sodium and paracetamol in pharmaceutical preparations is simple, rapid, and precise and can be used for routine qnality control. The method was also used to determine the amounts of diclofenac sodium and paracetamol in a mixture of their respective bulk drug powders.