Next gel gives us problems: Diprofylline 15 g Ruscustinctuur 3 G diphenhydramine HCl 300 mg Triamcinolone 10 mg Na Heparin 37,500 UI PF 1 gel AD 100 g

Methyl cellulosic gel, although little used, seems a good choice. Given you helpfull of a precipitate, which forms, I suppose the gel is initially clear and so the triamcinolone is dissolved? The precipitation is presumably diphenhydramine base. Indeed a solution with 1% diprofylline gives a pH vfan about 7. And in the gel we find 15 g diprofylline!

I see two possibilities to avoid this precipitation. One could lightly acidifying with a small amount of diluted acetic acid and set a pH of about 5.5. I hope that the added quantity is limited so that there is no adverse effect on the other components. Another approach consists of adding a small amount of alcohol, e.g. 10 à 20 ml, to try to bring the diphenhydramine back into solution. But in this case, methyl cellulose is not a good choice, given the incompatibility with alcohol. Therefore, I would replace it with 4 G hydroxyprpopylcellulose (Klucel GF).