# Advice on Separating Pseudoephedrine / Red #40



## SpectreOfCommunism (Jun 19, 2022)

I'll make this short -- the usual "wash with acetone until red color is gone" procedure does NOT seem to work with Sudafed (or at least generic SudaGest) 30mg pills anymore. The red coating is not iron oxide, rather it is Red #40 Aluminum Lake, which I can personally tell you is not particularly soluble in acetone. It IS soluble in both water and anhydrous ethanol, although it is not supposed to be -- according to my research, it should only be soluble in dry EtOH at 0.001g/100ml. In practice, however, it is soluble enough in dry EtOH that my pseudoephedrine hcl crystals are all reddish pink. 

Anyways, bottom line is that I have a ton of PE hydrochloride crystals that are all contaminated with this stuff and I am having a hard time separating them -- does anyone have any experience with this? Or alternatively, does anyone have any experience with Red #40 contamination and the Moscow route (I2 + red phosphorous) reduction and will it gunk up my final product?


----------



## MadHatter

Shake the pills in shaved ice first. It mechanically removes the bulk of the red layer.


----------



## G.Patton

Probably it is just dye


----------



## SpectreOfCommunism

Update: After a few pills in a few test tubes with a few test solutions, I've found that a bit of methanol with 0.5% acetic acid seems to remove the red layer nicely (~2min of agitation) and then, after throwing the de-coated pill into a mesh strainer, the methanol evaporates quickly enough to leave the solid white pill-core intact. I'm sure a very small amount of the PSE gets lost (since its also soluble in MeOH) but I think it's probably about the same (or possibly better) outcome as removing the layer mechanically. Although the red is gone, I can still make out the imprinted numbers on the brittle pill-core and I take that as evidence that very little pill material was removed. 

Ironically, this procedure relies on the binders and "gunk" to protect most of the PSE from dissolving in the methanol/acetic acid solution. Anyway, if anyone has any other ideas for how to improve the washing procedure, feel free to drop them here  thanks


----------



## G.Patton

I think you lose negligently small part of PSE by reason that active substance is located under tablet shell


----------

