TECHNOLOGY FOCUS - PHARMACEUTICALS - Preferred Method: The method comprises (i) using caulis sinomenii crude powder (500 or 400 or 200 or 800 parts by wt.), 0.5 or 0.3 or 0.2 or 0.8 mol/l hydrochloric acid (500 or 320 or 900 or 300 parts by vol.), wetting for 2 or 3.5 or 1 hour, installing percolation tube, adding hydrochloric acid (0.5 or 0.3 or 0.8 or 0.2 mol/l) so that liquid level covers 3 or 4 or 5 cm, impregnating for 24 or 6 or 15 or 36 hours, and percolating at a speed of 3 or 6 or 4 or 5 ml/minute for 15 or 8 or 20 hours, and stopping percolating to obtain percolation fluid, extracting by adding lime milk in percolation fluid to adjust the pH to 11.6 or 11.3, filtering, adding hydrochloric acid to adjust the pH to 8 or 8.5 or 9 or 7, extracting for 4 or 2 or 5 times by chloroform, mixing the chloroform layer and washing using water until it is neutral, adding anhydrous sodium sulfate (3% or 5% or 6%), vacuum extracting, concentrating and recycling chloroform, and crystallizing by dripping hydrochloric acid (6 mol/l) into the concentrate to adjust the pH to 3 or 4 or 2, stirring until the floating solid disperse, refrigerating, filtering, removing the filtrate, and drying the filter cake at 65 degrees C or 62 degrees C or 38 degrees C to obtain the yellow sinomenine hydrochloride crude product, and (ii) carrying out refining process by taking sinomenine hydrochloride crude product (7 or 10 or 8 or 6 parts by wt.), dissolving completely using 75% or 95% or 50% or 80% ethanol (60 or 120 or 12 or 40 parts by vol.) or heating and refluxing purified water, then adding activated carbon (4%), thermal insulating, refluxing for 20 or 25 or 15 minutes, filtering when it is hot, concentrating the filtrate, cooling, crystallizing, and filtering to obtain filter cake, using 95% of alcohol to wash filter cake until the filtrate is colorless to obtain sinomenine hydrochloride. The method comprises using water for injection, charging nitrogen, adding sinomenine hydrochloride and stirring to dissolve, and then adding sodium bisulfite and disodium edetate, stirring to dissolve, charging continuously nitrogen, adding activated carbon (0.1%), thermal insulating at 35-45 degrees C for 10 minutes, filtering to remove activated carbon, supplementing full amount of injection water, and filtering using 0.45 mu m and 0.22 mu m filter, sterilizing, and filling to obtain the sinomenine hydrochloride eye drop solution. The method comprises taking raw materials (in parts by wt.) sinomenine hydrochloride (25 or 35 or 20), sodium bisulfite (1 or 4.5 or 0.6), disodium edetate (0.3 or 1 or 0.2), and injection water to prepare 1000 parts by volume.