Zaobei Dan: A Topical Formula for Swollen Knees (Crane's-Knee Wind)

"Zaobei Dan" comes from Gufang Huijing (Essentials of Ancient Formulas). Its composition is: Chinese honeylocust fruit (Zaojia, seeds removed) 2, Chinese gall (Wubeizi, worms removed) and mirabilite (Poxiao) each 1 liang (30 g). Grind the herbs to powder; mix and pound with 4 liang (120 g) of first-press lees mash, 1 liang (30 g) of brown sugar, and an appropriate amount of ginger juice (60 ml), then steam until cooked. If the mixture is too dry, moisten it with distilled spirit. When using, take an appropriate amount of the medicine and apply it to the swollen knee, changing once daily.

This is a TCM topical formula for treating crane's-knee wind (hexifeng), with the action of reducing swelling and resolving toxicity. The crane's-knee wind it treats is a TCM disease whose main clinical symptom is a swollen knee; in modern medicine it is usually caused by bone tuberculosis, arthritis, or synovitis. Zaobei Dan uses local medication, acting directly on the lesion; it has few side effects and takes effect more easily.

The zaojia in this formula is the fruit of the leguminous honeylocust tree (Gleditsia sinensis). The formula requires removing the seeds; alternatively, zhuya zao (the immature, tooth-shaped fruit of honeylocust) may be used directly in place of zaojia. It has the same action as zaojia and is more commonly used in external medicine.