Interactions entre les seringues non réutilisables et les médicaments

Sorption studies of dipotassium clorazepate salt (Tranxène) and midazolam hydrochloride (Hypnovel) in polyvinyl chloride and glass infusion containers

The compatibilities of dipotassium clorazepate and midazolam hydrochloride with polyvinyl chloride (PVC) bags have been studied and compared with those observed with glass flasks. At room temperature, dipotassium clorazepate showed chemical instability which was independent of the container. At 4 degrees C, dipotassium clorazepate showed no decrease in concentration over 12 h, both in 5% dextrose solution and 0.9% sodium chloride solutions. When stored for longer periods of up to 72 h, a slight decrease not exceeding 5% was observed. The compatibility of midazolam with the PVC bags was found to be good at room temperature. It was slightly better in 5% dextrose solution than in 0.9% sodium chloride solution. High sorption of the drug was observed at pH 7.0 when the primary ring structure is maintained. The results make it possible for the hospital pharmacist to prepare dipotassium chlorazepate salt and midazolam admixtures up to 3 days before administration, provided the former are stocked in a refrigerator and the latter are prepared in dextrose isotonic solutions.

Leaching of antioxidants and vulcanization accelerators from rubber closures into drug preparations

A thin-layer chromatographic method was used to highlight the leaching into drug preparations of several constituents of elastomeric closures. Among the 150 preparations analysed, the twenty-eight local anaesthetics presented in single-dose delivery syringe-cartridges, one Epinephrine injection in prefilled syringes, eight insulin preparations and two Prednisolone acetate suspensions in the form of small volume flasks (less than or equal to 20 ml) were contaminated by one or more of the following: 2-mercaptobenzothiazole (MBT), 2-mercaptobenzothiazole disulphide and 2-mercaptobenzimidazole (MBI). Prednisolone acetate suspensions also contained 2,2'-methylene-bis(4-methyl-6-alpha-methylcyclohexylphenol). No contamination was found in drug preparations presented in large volume flasks (250-1000 ml). 2-(2-Hydroxyethylthio)-benzothiazole was not present, which indicated that the rubbers had not been sterilized with ethylene oxide. Elastomeric parts of drug closures analysed in the same way contained the same compounds as those found in drugs, one case excepted, which confirms the origin of the contamination. The lowest and the highest concentrations were found in syringe-cartridges; they ranged from 8.3 to 13.8 micrograms ml-1 for MBT, from 2.9 to 9.3 micrograms ml-1 for MBTS and from 2.8 to 11.1 micrograms ml-1 for MBI. Variable results were obtained, for a same preparation, depending upon the batches analysed, which indicates that rubber formulations and/or vulcanization conditions differed. The allergenic, toxic, embryotoxic and mutagenic properties of the compounds leached are discussed.

Thin-layer chromatographic analysis of phenolic age resisters in elastomers in contact with the body, drugs and foods

Phenolic antioxidants were identified by thin-layer chromatography in 102 samples of medical and pharmaceutical rubber articles. Acetone extracts of rubber were spotted on silica gel plates with a concentrating zone. Benzene, benzene-hexane (75:25) and benzene-ethyl acetate-acetone (100:5:1) were used as developing solvents and N-chloro-2,6-dichloro-p-benzoquinone monoimine as spray reagent. Only 8 sterically hindered phenols among the 57 previously listed were found in current use. Reasons for choosing these compounds and the experimental conditions are discussed.

[Characterization by thin layer chromatography of benzothiazole derivatives and beta-sitosterol leached by disposable syringes]

A thin-layer chromatographic study of 2-mercaptobenzothiazole, 2-(methylthio)benzothiazole, 2-(2-hydroxy-ethylthio)benzothiazole, 2-hydroxybenzothiazole, zinc 2-mercaptobenzothiazolate, mercaptobenzothiazole disulfide, and beta-sitosterol with three developing solvents and eleven spray reagents is reported. A simple method is described which highlights the leaching of 2-mercaptobenzothiazole and 2-(2-hydroxy-ethylthio)benzothiazole from the rubber plunger-seals of disposable syringes: contact of rubber with bidistilled water, extraction of this liquid with chloroform, chromatography on silica gel with the solvents previously studied and spraying with N-chloro-2,6-dichloro-p-benzoquinone monoimine. The method may also be used to discriminate those syringes sterilized with ethylene oxide, the only ones able to leach 2-(2-hydroxy-ethylthio)benzothiazole, from those sterilized by irradiation. Owing to the beta-sitosterol traces leached, it may also be used to investigate whether the plunger-seals are made of natural rubber. The toxic effects of the compounds leached are briefly reported.