The decomposition of phenylmercuric nitrate caused by disodium edetate in neomycin eye drops during the process of heat sterilization.
High-performance liquid chromatographic (HPLC) assays have been developed for phenylmercuric nitrate and mercuric ions in the presence of disodium edetate. Application of these methods to neomycin eye drops of the Pharmaceutical Codex and Australian Pharmaceutical Formulary, which contain both phenylmercuric nitrate and disodium edetate, show that edetate promotes approximately 20% decomposition of the phenylmercuric nitrate in the drops of the Pharmaceutical Codex but little in the drops of the Australian Pharmaceutical Formulary during sterilization by the recommended method. The reason for the stability of the organomercurial in the Australian product was determined as being due to the presence of sodium chloride in the formulation.
Parkin
J E
JE
School of Pharmacy, Curtin University of Technology, Western Australia.
Button
K L
KL
Maroudas
P A
PA
D002851:Chromatography, High Pressure Liquid; D004492:Edetic Acid / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D009355:Neomycin / Q000737:chemistry*; D009883:Ophthalmic Solutions; D010663:Phenylmercury Compounds / Q000737:chemistry*; D013242:Sterilization
D009883:Ophthalmic Solutions; D010663:Phenylmercury Compounds; D004492:Edetic Acid; D009355:Neomycin; C008860:phenylmercuric nitrate, basic