抄録
1) Change of activity in 0.05% aqueous solution of atropine sulfate with passage of time was examined by the anticholinergic action in excised intestine of guinea pigs and by mydriatic action in mice.
2) It was found with tests with excised intestine of guinea pigs that about 30% decrease in activity occurred on heating the solution at 80° for 1hour. The activity also decreased rapidly in the first few days when heated and unheated solutions were kept at 20°, but both solutions showed a definite value after 10 days, and no further change were seen to have occurred after 60 days of storage. The activity of the heated preparation after this lapse of time decreased to 30-40%, and that of unheated preparation to 10-15%.
3) According to tests of mydriatic action in mice, the efficacy of the solution stored for 66 days was no different from that of the fresh solution.
