How should ear drops containing 500kU colistin sulfate (Colimycine), 1% hydrocortisone acetate, and 2.5kU bacitracine in physiological water up to 5ml be prepared, which preservative should be added, and is a wetting agent such as propylene glycol necessary?

What is the correct preparation method for an O/W cream containing 60 g glycerin, 3 g salicylic acid, 1.50 g methylparahydroxybenzoate, 60 g sesame oil, 9 g tragacanth powder, and water up to 300 g, to prevent the formula from separating, and should alcohol, another gum, or a missing ingredient be added?

How do I prepare the following lotion: prednisolone 0.5%, salicylic acid 4%, propylene glycol 40 g, and water up to 100 cc?

How can 1% camphor be incorporated into an isopropanol-water solution for a prescription consisting of 3% salicylic acid, 3% precipitated sulfur, 3% resorcinol, 1% camphor, 1% Aerosil, 50 mg Tween 80, and 20 ml 70° isopropanol, with water added to reach a total of 100 ml?

How should I prepare a shampoo containing 25 g coal tar saponin, 18 g salicylic acid, 30 g lactic acid, 30 g urea, 4 g zinc sulfate, 18 g borax, and 48 g sodium lauryl sulfate with water added up to 600 g, considering that salicylic acid is poorly soluble in water and whether the combination of borax and zinc sulfate will result in precipitation?

How can the best suppositories be obtained for a prescription consisting of 50 mg rhatany dry extract and 20 mg ichthyol per suppository, for a total of ten units?

What are the stability problems of a solution containing 3 grams of Phenobarbital sodium and purified water up to 300 cc?