Interaction between chlorhexidine digluconate and EDTA.
The combination of chlorhexidine and EDTA produces a white precipitate. The aim of this study was to determine if the precipitate involves the chemical degradation of chlorhexidine. The precipitate was produced and redissolved in a known amount of dilute trifluoroacetic acid. The amount of chlorhexidine and EDTA present in the dissolved precipitate was determined by reverse-phase high performance liquid chromatography (HPLC) with ultraviolet detection at 288 nm. More than 90% of the precipitate's mass was found to be EDTA or chlorhexidine. The remainder is suspected to be water, gluconate, and sodium. Parachloroaniline, a potentially carcinogenic decomposition product of chlorhexidine, was not detected in the precipitate (the limit of detection was 1%). The molar ratio of chlorhexidine to EDTA in the precipitate was about 1.6 to 1. Based on the results, chlorhexidine forms a salt with EDTA rather than undergoing a chemical reaction.
Rasimick
Brian J
BJ
Essential Dental Laboratories, South Hackensack, NJ 07606, USA. brasimick@edsdental.com
Nekich
Michelle
M
Hladek
Megan M
MM
Musikant
Barry L
BL
Deutsch
Allan S
AS
D000814:Aniline Compounds / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry*; D011232:Chemical Precipitation; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004492:Edetic Acid / Q000737:chemistry*; D005942:Gluconates / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D012388:Root Canal Irrigants / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D014269:Trifluoroacetic Acid / Q000737:chemistry; D014867:Water / Q000737:chemistry
D000814:Aniline Compounds; D002614:Chelating Agents; D005942:Gluconates; D012388:Root Canal Irrigants; D012997:Solvents; D014867:Water; D004492:Edetic Acid; D012964:Sodium; D014269:Trifluoroacetic Acid; C010882:chlorhexidine gluconate; D002710:Chlorhexidine; C030691:gluconic acid; C004658:4-chloroaniline