DETERMINATION OF TOTAL ALKANNIN IN PHARMACEUTICAL PREPARATIONS BY DIFFERENTIAL-PULSE VOLTAMMETRY AND SPECTROPHOTOMETRY

Total alkannin was determined in pharmaceutical preparations by differ ential pulse voltammetry (DPV) and spectrophotometry after proper samp le preparation. For the sample pretreatment benzene, chloroform n-hexa ne, methanol, dimethylformamide and acetone as solvents were examined. The best results were obtained with acetone. Most wax and oil excipie nts were removed by filtration of the acetone dispersion solution of t he ointment sample, followed by evaporation. The residue was hydrolyze d for 8.5 or 3 h using 2% NaOH or 2M NaOH respectively. The detection limits were found to be 0.19 ppm with RSD less than 2.8% and 2.05 ppm with RSD less than 2.3% for differential pulse voltammetry and spectro photometry, respectively.