The effect of storage on the activity of adrenaline in local anaesthetic solutions: an evaluation using bioassay and fluorometric techniques.

The adrenaline content of local anaesthetic solutions has been assessed using a bioassay system and a fluorometric assay method. It was found that exposure of the solutions to daylight for a period of six months greatly reduced their adrenaline content, whereas storage of the same solutions under refrigeration or in the dark reduced the decrease in catecholamine content. Solutions containing adrenaline which were shown in the clinical situation to give inadequate anaesthesia were also tested. The analysis revealed a decline of catecholamine content in each solution.