Compounds and compositions are disclosed in which a quaternized drug unit is linked to a targeting ligand unit from which a tertiary amine-containing drug is released at the targeted site of action. Methods for treating diseases characterized by the targeted abnormal cells, such as cancer or an autoimmune disease using the compounds and compositions of the invention are also disclosed.本發明揭示如下化合物及組合物：其中四級胺化藥物單元連接至靶向配體單元，含三級胺藥物於靶向作用位點處自該靶向配體釋放。 亦揭示使用本發明之該等化合物及組合物治療特徵在於靶向異常細胞之疾病(例如癌症或自體免疫疾病)之方法。
