I need to prepare a solution in water of potassium permanganate for gynecological use, pH 8-9. I found a solution in the MTF to 0.025%.

Also in the National formulary is a 0.025% solution described but not of PH = 8. If such pH is desired then I would add 1.33 g of boric acid and 0.8 g of it per 100 ml. This is the isotonic buffer that can be used for Collyria.