Here's a tip you might want to try/include in the writeup. For a solid pre filter to get all the junk out that would clog the micron simply stuff a cotton ball or two down the barrel of the large syringe that is connected to the micron. The cotton will take care of all the big particles (and you would be surprised how great this is on its own for some pills- colored pill solutions come out clear) and the micron will do the fine detailing.
Yeah I actually think this is a great idea. Never thought of that actually. Saves time and cost of additional filters. Awesome!!
The only concern I have is keeping the cotton ball fixed at the end of the barrel if you are using a large diameter syringe. If the solution requires a bit of agitation (for uncrushed pills) the cotton ball can dislodge and get mixed into the suspension. It wouldn't do much harm, but would be kinda annoying if it happened. Nonetheless, good benefit/risk factor! :D
I think ^^ that was VERY good post with alot of very good information. Thanks for all your tips ED50of0.
Thanks for the feedback, jamesBrown. I am really glad you found the ideas helpful!
Having read just over half of the posts today, I realised captain already mentioned the inverted filtering method a few times near the beginning of the thread (my apologies). One caveat though, make sure the recipient vial has negative pressure maintained in it before injecting the final solution into it. Since by having the stopper upside down, any positive pressure MAY push out your hard-earned solution from where the needle punctures the stopper (this is especially true for larger volumes). The easiest way to ensure this doesn't happen is to:
1. If you are starting with an empty vial, inject the total volume of solvent you want in the end product into the vial first.
2. Equalize the pressure by detaching the syringe from the needle, which will let air out of the vial through the needle.
3. Attach a wheel filter to your syringe containing the pills.
4. Then attach this setup to the needle still stuck inside the recipient vial.
5. Draw your solution (slowly) from the vial into your syringe which will double to wet your filter and backwash any residue that be stuck to the inner side of it during production. If your solvent is sterile and contains no other percipitants, I don't think this will affect your filter. (can anyone confirm that filters can handle blackflushing with just solvent without affecting performance?)
6. Finally, carefully mix your suspension, let settle, and filter. Keeping the needle inside the vial to maintain pressure.
Alternatively, if you have a relatively short vial and have a long clean needle handy, you can skip most of the steps above and just stick a second syringe-less needle that's long enough to reach the end of the vial to let the air out when injecting your final product. I will have to draw a quick diagram to illustrate what I'm suggesting.
