Sequential Injection Method for the Determination of Oxprenolol in Pharmaceutical Products Using Chemometric Methods of Optimization

A sequential injection (SI) spectrophotometric method for the determination of oxprenolol in pharmaceutical products was developed. The method is based on the oxidation of oxprenolol on-line with Ce(IV) in sulfuric acid medium and the subsequent monitoring of the absorbance of the oxidized form of the drug at 480 nm. The procedure was optimized by the orthogonal array design at two and four levels. The factors included in the optimization were Ce(IV) concentration, sulfuric acid concentration, and the stop time of the composite zone at the reaction coil. The optimized SI system with a linear dynamic range of 50-400 ppm was found to be suitable for the assay of oxprenolol in pharmaceutical products.