I have an idea for extracting water-soluble compounds from gelled pills, but have none to try it on. Perhaps someone here would like to give it a go.
I read through patent # 4,070,494, which describes gelling pills, and is referenced by patent # 8,075,872 (the INTAC patent) as the basis of the gelling system. The basic idea is this: make the pills gel up when water is added, trapping the soluble compounds inside the gel network. After being swallowed, they slowly leach out by diffusion when they enter the small intestine.
So, I thought, how does one get the solution out of the gel? I think it can simply be leached out with water, without disrupting the gel network or having to use excessive amounts of solvent. A picture is worth a thousand words, so here is a simple cross-section drawing of my idea:
The big circle is the gelled pill, the small yellow one is the cotton, light blue is water, dark blue is your solution (see below), and the whole thing is on a small pedestal or perhaps the opening of a vial.
The idea is simple: gel the pill, then force water through it by osmotic pressure, from the center outward, displacing the solution stuck in the gel.
The procedure:
At first, the water will evaporate from the surface of the gel, sucking more water in through the cotton. As the process continues, however, the water-soluble stuff in the gel should form a very concentrated solution on the surface of the gel. At this point, the solution in the pill will be drawn out by osmotic pressure, and you should get some very concentrated solution dripping off. Keep the fan going the whole time to keep the surface solution concentrated.
That should get everything out, leaving a piece of inert gel behind. Use the liquid you've collected as you wish.
Well, that's my crazy idea. If someone tries this, please post your results.
I read through patent # 4,070,494, which describes gelling pills, and is referenced by patent # 8,075,872 (the INTAC patent) as the basis of the gelling system. The basic idea is this: make the pills gel up when water is added, trapping the soluble compounds inside the gel network. After being swallowed, they slowly leach out by diffusion when they enter the small intestine.
So, I thought, how does one get the solution out of the gel? I think it can simply be leached out with water, without disrupting the gel network or having to use excessive amounts of solvent. A picture is worth a thousand words, so here is a simple cross-section drawing of my idea:
The big circle is the gelled pill, the small yellow one is the cotton, light blue is water, dark blue is your solution (see below), and the whole thing is on a small pedestal or perhaps the opening of a vial.
The idea is simple: gel the pill, then force water through it by osmotic pressure, from the center outward, displacing the solution stuck in the gel.
The procedure:
- Gel the pill up.
- Using a pin / toothpick / whatever, poke a hole in the pill, down to the center.
- Stuff a small ball of cotton (bigger is better, but don't damage the gel) into the center of the pill.
- Push a thin tube full of water and connected to a reservoir of more water down the hole until it contacts the cotton. Two ideas for this are a needle / syringe and a pasteur pipette. Note that no pressure is required on the water and the pill should seal around the tube.
- If you're using a needle / syringe, cut the tip off the needle and sand / file down the outer edge of the tip until it no longer scratches a finger nail. Then attach it to a syringe (no plunger), fill it with water, and gently work the needle into the gel until it touches the cotton. Make sure not to get any gel / air bubbles into the needle.
- If you're using a pasteur pipette, fire polish the tip with a lighter or torch by holding it in the flame until the tip just starts to melt and it will no longer scratch a finger nail. Then fill the pipette with water and work the tip down to the cotton. Again, take care not to get any gel / air bubbles in there. I would recommend this approach since pasteur pipettes are clear glass, very cheap (they're sold in several-hundred packs) and disposable.
- Mount the whole thing as shown in the drawing, and point a fan at the pill so the entire surface is being blown on. Any old fan will do. If the gel is firm enough, the pedestal won't be necessary.
At first, the water will evaporate from the surface of the gel, sucking more water in through the cotton. As the process continues, however, the water-soluble stuff in the gel should form a very concentrated solution on the surface of the gel. At this point, the solution in the pill will be drawn out by osmotic pressure, and you should get some very concentrated solution dripping off. Keep the fan going the whole time to keep the surface solution concentrated.
- When all of the soluble stuff is pulled out of the pill, rinse the outside of the gel with a bit of water to get the last of the solution off. I have no idea how to gauge when the endpoint is or how much water you will need.
That should get everything out, leaving a piece of inert gel behind. Use the liquid you've collected as you wish.
Well, that's my crazy idea. If someone tries this, please post your results.
