import re

listofdci = [' Acid. L(+)-lacticum D4']
description = ' Acid. L(+)-lacticum D4 250 mg'

teste=[]
for x in listofdci:
    test2 = [f"{x}{y}" for x,y in re.findall(rf"{re.escape(x)}(?:\s*\([^()]*\))?\s*(\d+(?:[.,]\d+)*)\s*(m?g\b|)", description)]
    if test2:
        teste.extend(test2)
   
print(teste)