[pkuk]

HI, I am hopeless at chemistry and need some advice. I work as a vet.
I have a dog who I have prescribed a 4% solution of chlorhexidine to shampoo  over his body.  The thing is that this particular preparation does not lather well.  I tend to suggest using another basic shampoo that has a moisurising base to mix with it, so the chlorhexidine lathers a bit more and the skin can stay moisturised.  The thing is, if I mix 2 capfuls or however many of the chlorhexidine with a little bit of the other shampoo. will this dilute the chlorhex to a lower solution, say 3%, or will it still stay at 4%.  Sorry, probably a stupid question.

Thanks in advance

[chenbeier]

How do you prepare the 4% solution?
Instead of Shampoo A you use Shampoo B.

Or do you mix both?

[pkuk]

The 4% solution already comes made.
I mix it with the other shampoo which is also commercially made, but has no active ingredients (just moisturisers)

[chenbeier]

Ok then its like a dilution. Let say you have 1 liter 4% solution and you add 1 liter Shampoo. Then you have 2 liter of a 2% solution.

[pkuk]

ok, i get that, except in this case, I am going to apply a large strip of the shampoo B formulation on the animal and then will add 2 capfuls (arbitrary size) of the 4% chlorhexidine. So its not a equal by equal dilution per se, shampoo B is just acting as a moisturiser formulation.

Can I still get away with the 4% solution still being 4% ish by the time I have mixed both?

[chenbeier]

I doesnt matter what you mix. The new solution is everytime lower as 4%.

[pkuk]

ok cool
so if i just shampoo'd using the 4% solution and nothing else, i.e. mixing it water etc on the hair (as people do), then it will dilute it away from 4% anyway.
Do u think they make them a  little more concentrated then in order to account for this?

[chenbeier]

I dont think so. The solution is working how it is. I wouldnt worry about it.