Abstract
This study is on the effects of temperature, light and container type on the time course (1W, 2W, 3W, 1M, 2M, 3M) of the l-epirenamine reduction in local anesthetic agents. Lidocaine or prilocaine cartridge and lidocaine ampoule were prepared for this experiment. Assay of l-epirenamine was performed using electrochemical detector and high performance liquid chromatography. Loading conditions used in this experiment are as follows.
1) The levels of l-epirenamine had remained unchanged for three months, when kept in a refrigerator or a room regulated at 5+1°C or 23°C. Preservation at 30°C in an incubator, however, showed a decrease of 18% in three month. There was no difference in reduction rate between two kinds of containers.
2) The levels of l-epirenamine were remarkably decreased, when exposed to fluorescent or UV light in a room regulated at 23°C. Fluorescent light did not affect l-epirenamine levels in an ampoule but reduced those in a cartridge. UV light did not only decrease l-epirenamine levels in a cartridge but also in an ampoule.
3) When an ampoule, which was mixed with minced plunger gum and resealed with gassing nitrogen, was exposed to fluorescent light, the reduction rate of the l-epirenamine levels were the maximal compared with all other loading conditions. These results show that the following : High temperature, fluorescent or UV light caused reduction of l-epirenamine levels. l-epirenamine in ampoule is more stable than in cartridge. Heavy metal contained in plunger gum may catalyze l-epirenamine oxidation by light. The storage of the local anesthetic agents should be done in low temperature and in dark.
