VALIDATION OF THE METHOD FOR QUANTITATIVE DETERMINATION OF CHLORHEXIDINE BIGLUCONATE IN AN ANTISEPTIC MEDICINE
The aim of this work was to adapt and validate the method for quantitative determination of chlorhexidine bigluconate in the antiseptic medicine «Vitasept-SKO». The method for quantitative determination of chlorhexidine bigluconate by the absorption spectrophotometry in an antiseptic medicine containing ethanol 72,0±2,0 v/v % with 5,0±0,5 g/dm3 of chlorhexidine bigluconate was adapted and validated in terms of specificity, linearity, convergence, interlaboratory precision, accuracy and range of detectable contents. The method enabled the determination of chlorhexidine bigluconate in the presence of other components constituting the medicine. The value of the analytical signal obtained while studying placebo did not exceed by more than 2,0% in magnitude the value of the analytical signal corresponding to the lower limit of the measured content of chlorhexidine bigluconate in the drug. Therefore, the method is specific. The approximation coefficient must be at least 0,99 (0,9999). The intersection with the Y axis was no more than 2,0% of the value of the analytical signal corresponding to the 100% chlorhexidine bigluconate content (-0,24). The openability, calculated as the ratio between the average concentration determined according to the calibration curve and the nominal concentration, multiplied by 100% was within the limits of 98-102%. Hence, the method is linear. The relative standard deviation (RSD) for the quantitative determination of model solutions did not exceed 2,0%, consequently the method is precise. The degree of correspondence between the true value of the determined quantity and the results obtained by the validated method was established. The regularity is controlled by means of preparing model solutions of chlorhexidine bigluconate in the expected range of the determined content of the method. The range of the determined content according to the developed method makes up 4,5-5,5 mg/cm3 of chlorhexidine bigluconate.