DETERMINATION OF CHLORHEXIDINE DIGLUCONATE IN DISINFECTANTS

Chlorhexidine digluconate has been widely used in lenticular compositions, skin antiseptics and other ready-to-use disinfectants. This is due to its low toxicity, as well as a wide range of antimicrobial effects. A commonly used method for the analysis of commercially available chlorhexidine digluconate (usually available as a 20% aqueous solution) is high-performance liquid chromatography. In this article, the main methods of analysis used to determine chlorhexidine digluconate in disinfectants and skin antiseptics are considered. A new simple technique for the determination of chlorhexidine digluconate in technical products and disinfectants based on acid-base titration in alcohol-ketone is developed. It is shown that in this medium hydrochloric acid interacts with two nitrogen atoms of the chlorhexidine digluconate molecule. The end point of the titration is established by the transition of the blue color to green in the presence of bromophenol blue. The range of measured concentrations is from 0.1 to 2.0 mass%. The relative error of the method is 2.5% with the confidence probability P = 0.95. A comparison of the diode array detector and the charged aerosol detector for the determination of chlorhexidine digluconate has been performed. It is shown that a charged aerosol detector can be used to analyze chlorhexidine digluconate in cases where it is difficult to analyze with an ultraviolet or diode array detector. However, the sensitivity of the detector of charged aerosols is significantly lower than that of the diode matrix, and the linearity range is smaller. All methods were tested on model samples, as well as on samples of disinfectants, skin antiseptics, soaps and wipes with antibacterial effect.