This is a variant of Zhi Sou San (Stop Coughing Powder) from 1732. The formula was developed in order to treat an attack on the Lung by exogenous Wind. This formula has been enhanced with the addition of Fritillaria bulb (zhe bei mu) and Citrus fruit exocarp (ju hong).

When a pathogen enters the Lung it may transforms into Heat. The pathogens may obstruct the Lung Qi dynamic, resulting in the development of Phlegm. This scenario generally occurs as a consequence of Wind attack on the Exterior (either Wind-Cold or combined Wind-Cold and Wind-Heat). This formula is may therefore suitable for two different scenarios: either an acute stage or a subacute stage presentation. In the former, the exogenous pathogen may has passed from the Exterior into the Lung or has attacked the Lung directly. More commonly, the latter condition is seen in which an incompletely resolved Exterior syndrome (that may or may not have received treatment) progresses to an Interior one (i.e. the pathogens enter the Lung). There may or may not be a concomitant mild residual Exterior syndrome.

Finally, it should be noted that the formula’s Chinese name emphasises the fact that the cough to be treated is a deep productive one (sou) as opposed to a dry explosive one (ke).