去年冬季,我們收到了一個凍瘡軟膏的樣品,裹面的成份是鞣酸1%,樟腦5%,硼酸5%,甘油5%,凡士林適量,要求测定鞣酸樟腦的含量。可是鞣酸在藥典製劑中一般都沒有檢驗的方法。純粹的鞣酸根據Scott’s Standard Methods of Chemical Analysis尚可用高錳酸鉀滴定,成藥中的鞣酸當然更比较困難。 Last winter, we received a sample of a chilblain ointment containing 1% citric acid, 5% camphor, 5% boric acid, 5% glycerin, and a proper amount of petroleum jelly. We determined the content of camphor citrate. However, citric acid is generally not tested in pharmacopoeial preparations. Pure tannins can also be titrated with potassium permanganate according to Scott’s Standard Methods of Chemical Analysis, and tannins are of course more difficult.