Liquid chromatographic determination of residual hydrogen peroxide in pharmaceutical excipients using platinum and wired enzyme electrodes

Hydrogen peroxide (H 2O 2) is a chemically reactive reagent that can oxidize and degrade many pharmaceutical compounds under normal conditions. Unfortunately, H 2O 2 is often introduced into pharmaceutical excipients during manufacturing and it may significantly affect the chemical stability of drugs in formulations. Thus, a sensitive analytical method for determination of residual H 2O 2 in excipients is of importance in formulation development and product quality control. A liquid chromatographic system with a dual channel electrochemical detector (LCEC) was equipped with either a platinum electrode or a wired peroxidase electrode for determination of H 2O 2. The excipient (0.1 g) was dissolved in 10 ml of mobile phase and 5 μl of the dissolved solution was directly injected. The chromatographic run time for each sample was 1 min with a detection limit of 10 ng/ml (S/N=5) using the platinum electrode and 1 ng/ml (S/N=5) using the wired enzyme coated electrode, respectively. The peak purity was assured by comparing the peak ratios at different potentials for both the standard and the samples. The H 2O 2 levels in different batches of PVP, PEG, and other surfactants from different manufacturers were determined and the values ranged from 0 to 244 ppm. The LCEC method is exceptionally fast, accurate and convenient for quantitation of low levels of residual H 2O 2 in pharmaceutical formulation excipients.