Richard won't be the only one who can answer this, I'm sure.

When one buys a gel for topical application, what's in it that forms the gel?
I only know of gelatine and carrageenan to make a gel, and can't see that 
either of those would be used. 
What then?
Two queries prompt me here.

Firstly, I'm wondering how one could make a thicker topical preparation for CS 
or CS+DMSO than liquid, bearing in mind that the DMSO would carry any 
ingredients in very efficiently.  One might not wish to use ready-made products 
with possibly unwanted ingredients. 

Secondly, if one buys DMSO gel (thankfully I found the liquid), what 
ingredients are in the gel that would get carried into the body?

Thanks
Rowena