Some guars -especially the cheaper ones- are behave so badly. For example "N-Hance C261N". I tried to incorporate it in a shampoo in any possible way without sucess: pre-hydrate with citric, buffer with citrate, later addition directly to surfactants, addition with glycerin, change surfactants etc. Always precipitate from the 2nd day at 45c. Maybe some guars are not well manufactured. I have sucess only with Hydroxypropyl G.H.C. which is much more expensive!
Also the same bad results, with another cheap G.H.C.
Do you have any other idea to try with that guar?