What is the cause of the brown discoloration occurring after several weeks in a solution containing 200 mg chlorphenamine maleate, 400 mg phenylephrine HCl, 30 mg naphazoline HCl, 120 mg disodium phosphate, 100 mg monosodium phosphate, 610 mg NaCl, benzalkonium chloride, and EDTA up to 100 ml with water, and if it is due to the oxidation of chlorphenamine, what is the most suitable antioxidant, given the pH is approximately 6.8 and the phosphate concentration might be too low?

How should a 100 ml oral solution containing 240 mg gentamicin, 500 mg metronidazole, and lemon essence be prepared for a 14-year-old girl with cardiovascular issues and chronic diarrhea, considering that gentamicin is only available as 80 mg/2 ml ampoules, metronidazole is poorly soluble with a bad taste, and questions remain regarding the stability of gentamicin in solution, its oral absorption, and whether metronidazole should be dispensed in capsules to avoid interactions?

What product can replace triethanolamine, which is no longer reimbursed by the RIZIV, and what quantity should be used in a preparation containing 20 g urea, 60 mg betamethasone propionate, 16 g sweet almond oil, 8 g glyceryl monostearate, 6 units of the replacement, 85 g rose water, and 85 g water for preservation?

Given that Losec and Logastric contain gastro-resistant magnesium omeprazole, while omeprazole and some generics contain pure omeprazole, making the generic not identical to the specialty, what are the advantages of Mg-omeprazole, what can be prepared extemporaneously, and can capsules with a classic coating be used?

Can Tribvit be replicated as a compounded preparation, and what is the stability of such a formulation when prepared in capsules?

How can a pharmacist prepare a magistral formulation as a substitute for Terracortril suspension, which is unavailable until February, for a colleague urologist to use after certain surgical procedures in children, given the requested prescription of 5.7 mg oxytetracycline hydrochloride (as oxytetracycline), 17 mg hydrocortisone acetate, 11,400 U polymyxin B sulfate (as polymyxin B), and aluminum tristearate in liquid paraffin per 1 g?

Regarding the nasal drops containing 2.5 g phenylephrine HCl, 1 g naphazoline HCl, 5 g chlorobutol, 200 mg menthol, 5 drops eucalyptol, 20 ml glycerin, 10 drops Tween 80, 20 ml propylene glycol, and water up to 1 l, should glycerol and propylene glycol be included in the isotonicity calculations? Furthermore, given that 20 ml of glycerin and 20 ml of propylene glycol require 7.21 g and 9.27 g of NaCl respectively for 1 l of isotonic solution—making these drops highly hypertonic—is it correct that 20 ml of glycerol alone makes 0.8 l of water hypertonic?