Dual-mode determination of paracetamol and ibuprofen: Spectrophotometric detection via bisdemethoxycurcumin oxidative coupling and RP-HPLC quantification

In this work, we have developed rapid and accurate procedures to determine ibuprofen and paracetamol concentrations in both their pure and pharmaceutical forms. The first approach is a novel spectrophotometric method that depends on the formation of a complex resulting from the oxidative coupling reaction with an environmentally friendly reagent, bis-demethoxycurcumin (BDC). It exhibited good linearity over a concentration range of 10-40 µg/mL, with a detection limit of 1.49 µg/mL and a recovery of 99.90%. The second approach has been utilized by employing high-performance liquid chromatography (HPLC) for the simultaneous separation and quantification of both drugs. Thus, a mobile phase composed of acetonitrile, methanol, and water acidified with acetic acid (60:30:10, v/v/v) was used. In addition, a C18 column (150 × 4.6 mm, 5 μm) at a flow rate of 1.0 mL/ min and a column temperature of 35°C was utilized. This method demonstrated linearity over a concentration range of 10–60 µg/ mL for both drugs. According to the tailing factor, values were 1.283 for paracetamol and 1.358 for ibuprofen, and the recovery percentages were within the acceptable range (95.2–102.7%). Both methods were characterized by simplicity and accuracy and successfully determined the drugs in their pharmaceutical forms without interference from excipients. These results represent a scientific contribution, providing reliable and environmentally friendly analytical alternatives.