Now, we have a unique category of delivery vehicles called unstable phase mixtures.
So these are what we call biphasic liquids. So you can see an example here of a biphasic liquid.
If you look carefully on this bottle, there's actually two phases on the bottle.
On the bottom, there's a water phase and on the top, there's an oil phase.
Now you have to mix them into this kind of milky substance for it to be activated.
Now, why in the world would you have something like this?
Well, if you have a drug for example that will interact with the emulsifier,
you wanna keep them separate until the last possible moment.
Now, it's mostly used in so-called natural product
where the marketing strategy is to minimize ingredients with long names.
So I already told you that emulsifiers maintain a stable mixture of two products
that are normally non-mixable or immiscible.
So if you wanna avoid using the emulsifier which has a long name
and scares people without education, then you can use a biphasic liquid.
Emulsifiers that we commonly use so that we don't have to use a biphasic liquid include these different products.
All of these products are safe.
We also have unstable phase mixtures with biphasic suspensions.
So a suspension is a component that has a solid component, usually a powder.
And then the continuous phase which is some kind of a liquid.
The important aspect of this though is that the powdered substance is so heavy
that there is absolutely no way that they would maintain their stability.
Here is an example of a cosmetic product that actually uses it's -- they call it mud.
But really, it's crushed up rock that is suspended in an oil phase.
These are -- this one here is a cosmetic with a clay particle.
I can't really discern why people would use this product but it's actually fairly commonly used.
We also have tints, T-I-N-T-S, tints. These are often using metals and stone to give it color.
So an example of this are color rising topical paints.
Now, we don't think of this as a medication
but remember, patients are going to be applying these colorizing paints
to their skin during costumes and parades and things like that.
And these can have toxic consequences.
So we as physicians need to know how they're made, why they're made,
what they're doing with them and what the different components are.
There's other things that we also look at called supersaturated solutions.
And a really good example of that is supersaturated solution of potassium iodide.
Potassium iodide is a fairly heavy metal.
We sometimes use supersaturated solutions of potassium iodide
for the treatment of certain disease conditions like erytheme nodosum.
These are very hard to make. They often end up precipitating out.
But if you have a particularly skilled pharmacist,
they'll be able to maintain the saturated or supersaturated phase in a continuous stable medium.
Okay, that's it. I told you it would be quick, but it will be useful when you get out into practice.