Hi again,
First of all, I'd like to volunteer that I am no chemist, so if anyone would like to follow-up with better explanations or more strict interpretations, I'd certainly welcome it.
As I explained in my previous post, we are not trying to create a solution. As I understand it, solutions are where two (or more) elements or compounds mix together to form a homogeneous substance (mostly, liquids), but do not interact with each other. Instead, we are adding benzodiazepine (probably, more accurately, ground up particles of benzodiazepine bound to binding agent) to form a suspension. Suspensions always will settle over time (unlike solutions). However, some suspensions are better than others. We can use water to suspend our benzo-powder, but homogenised full-fat (4%) milk should work better. For one, milk is of greater viscosity, and this will slow the process of settlement. Secondly, most (but not all) benzodiazepines appear to have an affinity for fat, so they will have a tendency to bind with the fat in the milk. Homogenised milk has gone through a process to ensure that the fat is evenly distributed throughout the milk (older members will remember how the fat used to collect at the top of bottles of milk and we would shake it before opening - I certainly remember this).
Irrespective of the suspension medium (water, milk, juice, etc.), we can improve the suspension. Firstly, grind up your benzodiazepine into as fine a powder as possible. The finer the powder, the slower it will settle. Secondly, use more viscose liquids (full-fat milk rather than water, a smoothie rather than juice, for example). Thirdly, agitate the liquid immediately before you remove any liquid.
You should also consider how you agitate the liquid: you should shake it, or if this is not possible, make lots of up and down movements with a spoon or stirring rod (avoid actual stirring).
Stirring the liquid will create a vortex. Even if you shake the liquid, be sure to not add a rotational action, as this will induce a vortex. The reason why you should avoid a vortex is that this will create a concentration gradient radiating from the centre to the edge of the liquid. If the particles are denser than the liquid (this appears to be the case with benzos, as the powder tends to settle, not float in water or milk), then the particles will tend to be more concentrated towards the outside of the vortex. It appears that another force (I've just read about it, it is called diffusion flux) results in particles tending to move in the opposite direction (towards the centre) to until they reach a state of equilibrium. I assume this just means that the concentration of particles follows a curve, as all the particles do not gather at the very edge. Anyway, the concentration of particles is not even throughout the liquid - that's the point!
Because of the relatively low viscosity of water, and because the fat in homogenised milk appears to have an affinity for the benzo particles, I would recommend full-fat (4%) homogenised milk over water. However, whichever liquid you use, agitate the liquid - do not stir it. Use more viscose (thicker) liquids for a better suspension medium. Grind up the particles as small as possible (they will settle more slowly).
It is also possible to obtain suspension agents from the pharmacist. We've had posts about this (I thought we had one stickied) - if anyone finds a post, please reply with a link. These suspension agents should work very well, of course, so these would be my top recommendation.
I have never studied chemistry, so, someone - anyone, please feel free to tidy up my explanation.
Typos and small corrections.
