[Effect of different preparation crafts on the content of baicalin in shuanghuanglian (SHL) injection]. 
The content of baicalin is stable when baicalin is added quantitatively in preparation.  The time of extraction of the effective components of SHL with alcohol and the concentration of alcohol have little effect on the content of baicalin.  The components can be extracted once, and the content of alcohol is preferably 85%.  The pH level has greater influence on the content of baicalin, and should be controlled between 7.0 to 8.0.  0.2% activated carbon is suitable in preparation.