Pharmaceutical Affairs Act Article 51

Dealers of western pharmaceuticals cannot concurrently sell Chinese medicines, and vice versa, except for general sale medicines.
中文原文 藥事法第51條
西藥販賣業者,不得兼售中藥;中藥販賣業者,不得兼售西藥。
但成藥不在此限。

English translation for reference only; the Chinese text prevails. Not legal advice.