Please help! Emulsion while extracting pseudoephedrine!

[zeyeonist67]

This is my first post here so I hope it's in the right section. I have a major issue here with extraction of pseudo from OTC tablets. I went with the "Full turps cure" method and modifies it to include an A/B extraction at the end.

The ingredients in these pills are as follows:

Pseudoephedrine HCl - 60mg

Acetaminophen - 500mg

Inactives:

Corn starch

Crospovidone

Magnesium stearate

Stearic acid

POVIDONE

Microcrystalline cellulose

Silicon dioxide



4 boxes of 24 caplets was used (5.760g pseudo)

Now because these have so much acetaminophen, first i did 3 acetone boils to remove acetaminophen and any other acetone soluble ingredients. Carefully decanted and set aside the spent solvent to distill back later for recycling. I did this first as in previous experiences acetaminophen really fucks up the rest of the procedures.

Now what I should have done next was the first step of the turns cure, and soak in hot xylene/mineral turps for 12hrs. But I foolishly skipped this step due to the stink of these solvents. So I proceeded to do the alcohol extractions. Twice with 99% IPA, and once with methanol. Upon evaporation of alc I got a measly 0.20g of extract!!! This really confused me. So that's why I added in the A/B extraction to see if that could extract the goods. I put the dried powder pill mass into a 150mL flask and with distilled water shook the hell out of it for about 10 minutes then let settle for 30mins and filtered tye solution, then when all the water passed thru filter, making sure it was not containing sediment, I dried the pill mass in the filter, and repeated this 3 or 4 times and combined the water extracts.

This is where things got messy.

I basified the solution with NaOH, and I immediately saw the pseudo freebase float uo to the top, which was a wonderful sign, but within minutes quickly disappeared! So I added xylene to extract tge freebase, added salt, added more naoh then shook the solution just to get an absolutely HORRIBLE emulsion that I have had hell trying to deal with. I tried adding more salt until it was saturated, more naoh, but nothing has worked! I even tried concentrated hydrogen peroxide (~20-25%) which almost seemed like it was helping, but I barely had much left and used it all up, still to no avail. So I went ahead and separated tye layers, and took the xylene pulls, washed with dH20 separated, then with acidification H20 with Hcl, evaporated my water (and hopefully pseudo hcl) and got a measly 0.21g of crude pseudo. Totalling 0.41g of pseudo from 5.76g I put in.

I'm assuming tye pseudo is still in the emulsion water. Any help please send thank you!

 

[NelsonBandit]

Same here, can't extract barely anything... I'm surprised you saw the freebase when adding NaOH, I can't even get that to work.

 

[HenryWeston]

J

 

[HenryWeston]

Resolving the dreaded emulsion.

• if using sudafed, remove red coating via various methods, mechanical or chemical.
• use a good plastic fizzy drink bottle (coca cola etc) with decent amount of headroom. Remember to vent carefully, good idea to collapse bottle before mixing. Slosh or tip the mixture.
• Always add toluene before addition of NaOH.
• MOST IMPORTANTLY. you must get a feel for whats going on, observe it. Dont just shake wildly and hope for the best. Unless you have the perfect ratio.
• work on about 1 capful of caustic soda to 6 packets of pills. (Note this is for uk hardware store caustic soda cap sizes) 2 caps 12 packets etc
• just enough water to dissolve powdered pills
• just enough water to dissolve naoh
• Add the caustic to your mix of dissolved pills and excess toluene (2-3 times the amount of water/pill mix)

• if the ratio is good you will be able to shake it like mad and the whole pill mass will congeal and you’ll have nice clean toluene.

!!Beating the devilish emulsion!!

• the best method i found is to use a heatgun and heat the emulsified layer.
first, add non iodised table salt, this can often break the bubbles. There is usually a water layer at the bottom and the toluene (np solvent) is full of emulsified gak.
Heating the toluene gak mix only, best in a beaker, all the way around. The hot toluene will free itself from the gak.
keep doing this until you achieve a satisfactory result and decant to a cotton wool plug in a funnel. A layer of naoh on top of plug will trap any entrained water.

other methods.
• pour the emulsion down a glass rod or similar onto the wall of a beaker. This can enable the separation.
•use a vibrating device (use your imagination) to vibrate the vessel the emulsion is in.
• create a centrifuge by putting emulsion in plastic bottle and securely tying a cord round the neck. Swing it round your head or to the side while keeping your swinging hand in the same point.
• sometimes a careful fiddle with a glass rod can resolve it.

Your always going to encounter product loss when you get an emulsion and everytime you transfer from one container to the other.

again, the most important thing is observation and getting a feeling for whats going on.
When u get it right, it can be a few shakes and you get complete separation. And it sounds a bit like shaking gravel or an heavy elastic lump in the bottle and your toluene wil be crystal clear.

dont expect to get it right if your new to this.
If your in the uk, and can get boots or care+ just methanol extract the powdered pills. And filter. No need for base