Anti-parasitic Active Pharmaceutical Intermediates Raw Chlorhexidine Gluconate CAS 18472-51-0

Chlorhexidine digluconate is commercially available as a 20% (w/v) aqueous solution since the substance cannot be isolated as a solid. It is soluble in water to at least 50% (w/v) but high viscosity makes such concentrated solutions inconvenient to use. Autoclaving of solutions greater than 1.0% can result in the formation of insoluble residues and is therefore unsuitable.

If sterile solutions are required at such high concentrations, then filtration through a 0.22 m membrane filter is recommended. Dilute chlorhexidine solutions may be stored at room temperature, and a shelf-life of at least 1 year can be expected, provided that the packaging is adequate. Prolonged exposure to high temperature or light is to be avoided because this can adversely affect the stability of chlorhexidine solutions. All dilute solutions to be stored should be either heat-treated (sterilized or pasteurized) or chemically preserved (4% isopropanol or 7% ethanol) to eliminate the possibility of microbial contamination. For autoclaved solutions the choice of container material is important, best results being achieved with neutral glass or polypropylene. If soda glass is used with chlorhexidine solutions the resultant pH may be above that which is considered optimal for stability (pH 5-7)because of leaching of alkaline materials from the bottle".