Sinomenine hydrochloride is generally produced from

Caulis Sinomenii

. At present

the purification process in industrial production suffers from large amount of solid waste

high solvent toxicity

and low sinomenine hydrochloride yield. In this study

a new purification process for sinomenine hydrochloride was proposed by using the extract obtained from acid extraction of

Caulis Sinomenii

as the starting material. The process included the following steps: alkalization

extraction

water washing

acid–water stripping

drying

and crystallization. 1-Heptanol was used as the extractant. The distribution coefficients of sinomenine and sinomenine hydrochloride in 1-heptanol–water system were 27.4 and 0.0167

respectively. The dissociation constants of sinomenine hydrochloride were 8.27 and 11.24

respectively. Process parameters of the new purification process were optimized with experimental design. The extractant 1-heptanol and sinomenine hydrochloride in the crystallization mother solution can be recycled in the new process. The purity of the obtained sinomenine hydrochloride crystals exceeded 85%

and the yield was about 70%. Compared with current industrial processes

safer extractant

less solid waste

and higher sinomenine hyd

rochloride yield can be achieved using the new purification process of sinomenine hydrochloride provided in this study.