HPLC Method for Simultaneous Determination of Ascorbic acid, Phenylephrine, Paracetamol, Caffeine in Their Pure and Dosage Forms

An isocratic HPLC method has been developed for determination of ascorbic acid, phenylephrine, paracetamol, and caffeine in their pure and tablet forms. Separation was carried out at room temperature on an Kinetex 2.6 C18 100A (4.6 mm × 100 mm) column using a mobile phase of 0.05 M potassium dihydrogen phosphate buffer (pH 3.50 by ortho-phosphoric acid): acetonitrile: methanol (70:20:10). The flow rate was 1 mL/min, maximum absorption was measured at 220 nm and linearity was in the range of 1-50 μg/mL for all drugs. The retention times of ascorbic acid, phenylephrine, paracetamol and caffeine were reported to be 1.83, 2.94, 3.74 and 5.13 minutes, respectively, indicating a very short analysis time compared with other reported methods. Also, limits of detection were reported to be 0.76, 0.82, 0.47 and 0.24 μg/mL for ascorbic acid, phenylephrine, paracetamol, and caffeine respectively, showing a high degree of the method sensitivity. The proposed method was validated in terms of linearity, accuracy, precision and robustness according to ICH guidelines and results were compared statistically with reference methods in respect of precision and accuracy.