for the following products
(6R)-5,6,7,8-Tetrahydro-L-biopterin dihydrochloride | (6R)-Tetrahydro-L-biopterin dihydrochloride | (R)-2-Amino-6-((1R,2S)-1,2-dihydroxypropyl)-5,6,7,8-tetrahydropteridin-4(3H)-one di hydrochloride and Sapropterin dihydrochloride