Chromatographic Application on Calixarene Bonded Stationary Phases: A Stability Indicating Method for Simultaneous Determination of Paracetamol, Caffeine and Acetylsalicylic Acid in Excedrin Tablets

A simple, rapid and accurate, routine-LC method is described for simultaneous determination of paracetamol, caffeine and acetylsalicylic acid in a tablet formulation. This study represents a new application for the calixarene stationary phases. The chromatographic separation of the three pharmaceuticals was achieved on a Caltrex BIIE column (250 x 4 mm, 5 mu m) using a binary mobile phase of 14\% ACN and 86\% 50 mM NaH(2)PO(4) pH 3.0 at 1 mL min(-1) flow rate. Detection was at 214 nm. Separation was achieved in less than 15 min. The method was validated for system efficiency, linearity, accuracy, precision, limit of detection and quantification, specificity, stability and robustness. The limits of detection were 4.88, 9.77 and 78.13 ng per 10 mu L of their injected volumes, respectively. The recovery values of this method were between 94.63 and 101.85 and the reproducibility was within 3.88. The method could also be used for separation and determination of salicylic acid which is considered the most important degradation product of acetylsalicylic acid.