Need some math checking

[Coolwhip]

This isn't NSPD, but the forum I think I will get the most accurate help from, feel free to move it though if you see the need. Is harm reduction.

If I've got 2 substances, 1 active, 1 not, both have a density of about .9g/mL and I want to put them into capsules that hold .13mL what ratio do I need to mix them in to have 15-20mg active per capsule.

I could figure this out from there, but if someone wants to go ahead and tell me to make sure I'm doing this right, how much cut to have a ~17% active mixture with 1 gram active and again 3 grams active, and then how much of said mixture(in mass) to fill 100 of said .13mL capsules.

Also I'd rather err on the side of caution and have weaker capsules, so maybe just ~15mg instead of 15-20. Or one answer for 15, another for 20.

And this isn't for dealing, but I won't be the only one ingesting them which is why I want to make sure this is right, and no worries, 20mg is less than a recreational dosage.

edit: Full disclosure for safety, it is 3-FPM and baking soda. I know baking soda is listed as .7g/mL but mine is slightly more than .9, I assume from moisture content. And I am assuming taking up to 4-6 of these throughout the day(never more than 2 or 3 at once) is not a problem from the baking soda, even though it is dry. If so, maybe someone could offer up a different cut that is also around .9g/mL(same as the 3-FPM); I don't want to stray too far from that to something like calcium carbonate because AFAIK matching the densities makes for more even mixing.

 

[neurotic]

Let me see if I understood correctly: you want to mix the two substances in a way such that you can just scoop 0.13mL of the resulting mixture into a capsule, making it so there's 15mg of 3-FPM inside that capsule?

Isn't though generally regarded that there is no safe way to evenly mix solids that way???

Assuming there is a way to mix the two powders and guarantee a proper mixture: if 1mL of 3-FPM is 900mg of 3-FPM then 0.13mL of 3-FPM is 117mg. Likewise for the cut. And you want to mix the two powders so that 117mg of the resulting mixture contains 15mg of 3-FPM. So 117mg of your ideal resulting mixture will have to contain 102mg of the cut. Thus, assuming the cut and the 3-FPM are of same density, for every 15mg of 3-FPM there should be 102mg of cut.

Assuming there is no way to mix the powders safely I would not do that unless you can risk taking a capsule that contains 117mg of 3-FPM.

Can't you alternatively dissolve the 3-FPM in something and use a syringe?

 

[sekio]

You can't rely on dry-mixed powders being evenly distributed. Also, 3-FPM will react with baking soda to form a freebase. If you can't figure out the math for dilutions like that, then maybe you should stick to a simple volumetric solution.

Don't rely on the capsules being of equal volume either, filling them by volume is bound to have errors. Always fill by weight.

If you want to really ensure you get a homogenous mix, dissolve the 3FPM in a volatile solvent and then add it to powdered sugar/starch/cut and evaporate the solvent with thorough mixing.

Really though, aqueous solutions are the way to go.

 

[adder]

What does density of a solid (do you really mean it?) have to do with the volume of a solution of it? I'm not following this bit. If you do mean density of a solid, then 0.7 or 0.9g/ml is certainly not the density of baking soda either, way too low. It looks more like a number representing solubility in water, but it's wrong too, it's ~100g/L at room temperature, so definitely not 0.9g/ml.

If you mean solubility in water, and you want to first prepare a saturated solution by adding more and more until no more dissolves, and then judge the amount of a substance by the volume of its saturated solution measured out, it won't work at all. First of all, 0.9g/ml is a pretty rough number when it comes to drugs, besides when you prepare a saturated solution of 3-FPM you can't be sure its concentration is 0.9g/ml, generally using solubility of a substance (even from literature) as a guidance of how much you're about to ingest judging by the volume of a saturated solution is a bad idea. Basically you do need a scale.

I know baking soda is listed as .7g/mL but mine is slightly more than .9, I assume from moisture content.

No idea what you mean here, perhaps it's time for me to get some sleep...

 

[Coolwhip]

No not scoop, using a capsule filling machine.

 

[Coolwhip]

If it were just for me, I'd just use fractional dilution and go from there, but someone close to me wants capsules and I was hoping I could aim for 15mg and by doing so end up with 30mg or less per capsule.

The density of a powder(like arm and hammer), I know this changes with particle size and moisture content, but the arm and hammer in my cupboard is just over a mL per gram(and hence, just under a gram per mL), not a block of sodium bicarbonate. I thought what I meant was fairly simple, I want to be able to mix 3-FPM and a cut together, had baking soda in mind, and then use a capsule filling machine to fill number 5 capsules which hold .13mL and end up with 15-25mg of 3-FPM per capsule. I don't need to be completely precise and I'm not exetremely worried about hotspots(I won't be mixing ounces at a time, a half gram to a gram of 3-FPM at most for the first time, if it worked well might step it up to 3) I would rather the pills end up closer to 15mg than 25mg though, even under if it came down to it. I'm not mixing fentanyl here and people regular consume 100mg+ of 3-FPM at a time. And I know you can't mix powders homogenously, which is why I haven't counted on precese measurements and have been trying to err on the side of caution the entire way to end up with weak pills.

If the powder is .8g/mL the capsule should hold 105mg if it is 1g/mL it should hold 130mg.

Neurotics answer was what I was looking for as far as that goes. I was hoping it would be as simple as that.

But sekios answer is why I gave full disclosure, and appreciate it for harm reduction, so if its not as simple as that, and I continue to ignore hotspots, then just have to deal with the issue of the capsules not holding .13mL then would this work...

Ok, so confectioners sugar or corn starch instead(or whatever), since you are saying for mixing purposes the densities of the powders don't need to match(as in it will be equally as 'dangerous' either way), I guess my only choice is to find out how much cut it takes to fill 100(or 20, size of machine) capsules(in mass) by weighing said number of capsules, filling them with cut, then reweighing and subtracting the first number, then subtract desired amount of 3-FPM from that number, mix in said amount of 3-FPM to end with 15mg per and go from there, would that be close enough that I'm not going to end up with very many capsules of more than 30mg, or a hot one with more than 50mg? Assuming the powders are fairly well mixed, surely I can mix them well enough that any given volume of .1mL to .15mL won't be 50% active

If you are saying that just won't work and I will end up with large hotspots without using a solvent and evaporating, I guess I'll go from there, any suggestions on the solvent?(or give talking her into a nasal spray another shot, although she seems dead set on nothing but oral consumption or a dropper if someone can give some tips on how to deal with the taste)

My point being I don't plan on a lot being dosed at once, and would rather she take 8 throughout the day, than take 2 and feel it more than wanted. How low do I need to aim to ensure that 90% of the capsules will have less than 30mg...or does no one have enough knowledge/experience mixing powders to tell me that, or do they have enough knowledge to tell me I shouldn't try.

And thank you everyone for your help and concern.

EDIT: On second thought, I've decided just to forego the mixing of powders, its just not worth the risk when I'm not the one eating these, dissolving and drying is an easy enough step, question remains any suggestions on the solvent and the cut I should use with it?(as far as suitability, solubility, safety, and price)

 

[serotonin2A]

Capsules should never be filled this way. If you want 15 mg per capsule then the correct way to do this is fill the capsule by weight. You can either fill the capsule with a certain amount of the diluted drug (if you manage to make a homogenous mixture), or put 15 mg of the pure drug into an empty capsule and then fill it up the rest of the way with an inert filler such as cornstarch or lactose.

 

[Coolwhip]

I get that now, see my second large paragraph above...I was just hoping to have a ballpark figure before I made the mixture, since I can't know how much of anything fits into the capsule without either a)knowing the g/mL or b) filling the capsules first then finding out how much they hold. Putting 15mg into capsules one by one would be quite tedious.

After a couple PMs I am definitely going to take Sekio's advice to...

dissolve the 3FPM in a volatile solvent and then add it to powdered sugar/starch/cut and evaporate the solvent with thorough mixing.

You can close this thread, but I will say to anyone who stumbles upon it you should just use a volumetric solution for the highest level of ease and safety, unless you just really need to get something into capsules for whatever reason, thanks everyone for your contributions.

 

[d1nach]

Well first off baking soda has many densities depending on how many water molecules are attached

2.54 g/cm3 (25 °C, anhydrous)
1.92 g/cm3 (856 °C)
2.25 g/cm3 (monohydrate)[1]
1.51 g/cm3 (heptahydrate)
1.46 g/cm3 (decahydrate)[2] (wiki)

Secondly, commercial baking soda varies in density.

Therefore, i think your asking for trouble and if i was you id not even make an attempt because of how high the risk is

 

[adder]

If the powder is .8g/mL

That's a very ambiguous phrase, you see, referring to this as density is also very misleading as density means how much a unit of volume of a substance weighs, so its mass per unit of its volume, whenever you refer to a solution of a substance, it's concentration (of a solution), mass or quantity (mol, mmol etc.) per unit of solution's volume. Hence the misunderstanding, I'm not nitpicking, it's really important to make such things as clear as possible, otherwise indeed you may be in for trouble. It seemed very odd from start that you would be able to measure density of your baking soda. Anyway, again, to make sure each capsule contains the same amount of your substance, it would be best to weigh a certain mass, and insert it into a capsule, and then add a filler.

 

[Coolwhip]

It's not hard to measure the density of baking soda at all actually, especially small amounts when you own your own torch(which I do) but doesn't matter now, problem is solved.