How can precipitation be avoided in a nasal solution containing 682 mg tetracaine HCl, 15 mg sodium metabisulfite, 270 mg NaCl, 0.37 ml adrenaline (1 mg/ml), and aqua conservans up to 300 ml, given that crystals form when stored in the refrigerator (even when using Sterop or Suprarenin ampoules) but dissolve at room temperature at pH 7, and how long is this solution stable when refrigerated?

Can the flavor of a flavored omeprazole suspension be further improved?

What is the shelf life of an erythromycin lotion containing 2 g erythromycin, 2 g resorcinol, 50 g isopropanol, 1 g lemon spirit, and hamamelis water up to 200 g?

What is the best way to prepare 200 g of a complex ointment for chronic conditions and back pain, containing 1.5 g Carbomer 980, 9 g white vaseline, 8 g distilled water, 2 g propylene glycol, 3 g Lanette N, 2.5 g liquid paraffin, 3.3 g capsicum oleoresin PBV, 2 g tromethamol, and 75 g DMSO?

How can a hydro-alcoholic lotion containing 1.5 g menthol, 3 g benzophenol, 3 g glycerol, 15 g spiritus, and aqua up to 250 ml be prepared if the menthol does not dissolve, should liquid or crystalline benzophenol be used, and is there a difference in strength or application area between these forms?

What is the correct preparation method for a moisturizing body milk containing 10 g urea, 2.5 g lactic acid, 2.5 g lanette wax SX, 2.5 g arachis oil, and aqua up to 100 ml, given that dissolving the urea and lactic acid in heated water and mixing it with the melted wax and oil at the same temperature resulted in separation, which persisted as a very liquid mixture with two distinct phases even after the addition of Tween 80?

What is the recommended preparation method for a hemorrhoid cream containing 8 g liquid fat-soluble witch hazel extract, 4 g water-soluble horse chestnut extract, 9 g Cutina, 0.5 g cetyl alcohol, 0.5 g lanolin, 0.5 g triethanolamine, 4 g sorbitol 70%, 0.1 g alpha-tocopherol, 0.12 g nipagine, and distilled water up to 100 g, given that the resulting cream is too liquid and not homogeneous, and can the unavailable horse chestnut liquid extract be replaced with mother tincture?