Following preparation gives a precipitate: resorcinol 1g alum 1g Boric acid 1g erythromycin 1g Isopropyl Alcohol 60 ml water AD 100 g

This composition seems to me an old formula, which is modernized by adding erythromycin. An analogue composition is in question: ' How do I prepare: ' But here the matter is even more complicated due to the presence of erythromycin. This means that we can lower the amount of isopropyl alcohol little to increase the amount of water in order to keep alum in solution.

I would therefore follow the answer 1 of question 57: After precipitation of the insoluble portion of alums and decanting of the clear liquid, this liquid erythromycin is dissolved. It is not ruled out that proposal 4 is also feasible.