| References | The dc-polarographic investigation of antazoline hydrochloride in aqueous acidic media is described. Using potassium chloride-hydrochloric acid mixture as the supporting electrolyte (pH = 3.25), antazoline hydrochloride was electrochemically reduced at the dropping mercury electrode, with the production of two waves with E1/2 values of --1.35 and --1.65 V respectively. As revealed from the study of the effect of mercury column height, pH of the medium and concentration of the depolarizer, the polarographic reduction of the antazolinium cation is preceded by a catalytic H-wave. The diffusion-controlled nature of the electrode process permitted the quantitative determination of antazoline hydrochloride in concentrations down to 1.0 . 10(-4)M. Application of the presented procedure to the analysis of different dosage forms of the compound studied proved successful and compared favourably with official estimations of anatazoline salts. In view of its simplicity, accuracy and sensitivity, the presented polarographic method can be recommended for routine analysis of antazoline formulations. Issa I M, Omar N M, El-Shabouri S R, et al. Polarographic estimation of antazoline hydrochloride[J]. Die Pharmazie, 1978, 33(8): 513-515. In order to evaluate the pharmacokinetics characteristic of antazoline hydrochloride in Beagle dogs, a sensitive and specific HPLC method was developed and validated using phenacetin as the internal standard (IS). The analyte and the IS were extracted from dog plasma by ethyl acetate under the basic condition. The analyte was separated by a C18 column and detected with a variable wavelength UV-detector. The mobile phase consisted of methanol-5mmolL(-1) tetrabutyl ammonium bromide (45:55, v/v) containing 0.5% glacial acetic acid in a flow rate of 1.0mLmin(-1). Standard calibration graph for antazoline was linear over a curve range of 20-1600ngmL(-1) (R>0.99) and the lower limit of quantification was 20ngmL(-1) using a plasma sample of 500μL. The intra- and inter-day precision values were less than 14.3% relative standard deviation (RSD). The intra-day assay accuracy was in the range of 98.1-100.6% and the inter-day assay accuracy in the range of 99.2-101.1%. The extraction recoveries were on the average of 88.4% for antazoline and 76.8% for IS. Plasma samples were stable at least for 1 month at -20℃. This method was successfully applied to pharmacokinetics study of antazoline after intravenous administration to Beagle dogs. Li X, Chu Y, Ke Y, et al. Determination of antazoline hydrochloride in Beagle dog plasma by HPLC-UV and its application to pharmacokinetics[J]. Journal of Chromatography B, 2013, 929: 97-101. |
