Solubility Question for the Chemistry Geeks

[iloominati]

I know that the mixed amphetamine salts in Adderall IR are soluble in H2O at the rate of 1:8.8 at 60 degrees. So, 30mg dissolves in .45ml H2O. The question I have is how quickly do they dissolve, and more specifically how much longer does it take to dissolve in very cold water, i.e. 35 degrees? Also, how much additional water is required since the mixed amphetamine salts pills have 270mg of fillers (each 30mg pill weighs appx. 300mg)?

So the question boils down to this: How much 35 degree H2O do I need to dissolve 60mg mixed amph. salts and how long do I need to stir/shake/mix it? Actually all I really need is the equation since I have all the inputs.

Any ideas?

 

[strat54]

Idk how to account for the water temp but u shouldn't have to add water for the fillets because u don't want to dissolve them anyway right?

 

[23536]

there is no one-size-fits-all formula that has temperature as a variable is there? Especially when you're studying such a mixture of things as a pharmaceutical tablet.

I mean, you'd need a coefficient for each type of pill mash, and you'd need to determine that coefficient by experimentation.

solubility in near-freezing water vs. water at room temperature vs. water at body temperature are possibly all described by different functions. Or they're all related by something complicated like

 

[sekio]

Dunno what the ideal gas law has to do with this.

If you're going to be extracting amphetamine out of adderall xr you should do an acid/base extraction or go home; you're not going to be able to selectively dissolve the amphetamine out. The sulphate salt is soluble 50-100mg/ml in warm water, probably more in hot water.

 

[23536]

Dunno what the ideal gas law has to do with this.

This one is for liquids. I found it in Marcus' The Properties of Solvents in this paragraph:

For liquids, however, the equation of state depends in a more complicated form on the intermolecular potential energy u(r) and
the pair correlation function g(r):

but a discussion of this subject is outside the scope of this book.

besides that, yeah, I don't have a clue. I'd like to know though.

 

[mgrady3]

good luck calculating the intermolecular potential energy in the amphetamine you want to extract and better luck for all the random filler that are partially soluble;

ie. That equation will not help other than in the explanation that solubility is not governed by one simple function of temperature of solvent.

so the simple answer to the OP is, the "equation" you want does not exist. (one where you just plug in the numbers you gave us and out falls the amount of h2o needed)
but,
why are you wanting to use 35 degree water in the first place? As mentioned earlier a water extraction isn't particularly helpful for adderal.