How can we prepare atropine sulfate 0.5% eye drops without a preservative?

What went wrong when flakes formed upon adding 50 g of Carbopol gel to a homogeneous mixture of 1 g erythromycin (rubbed with propylene glycol) and 2.5 g benzoyl peroxide (rubbed with chloroform in a mortar to a homogeneous powder)?

How can Protargol 50 mg suppositories be prepared to achieve a homogeneous color and consistency, given that the raw material from a new supplier and production process—which Certa acknowledges—results in uneven, light gray suppositories when using the previous method of moistening the powder with Miglyol and rubbing it with half of the melted suppository base?

What is the best way to prepare a lotion containing 26.4 g sweet almond oil, 10.8 g hydrogenated palm oil, 1.5 g stearic acid, 2.5 g cetyl alcohol, 3.3 g PEG-400 monostearate, 0.45 g boric acid, and 180 ml aqua conservans, and is it possible to use Lanette SX as a substitute since polyethylene glycol 400 stearate is no longer available?

Why does a 13% carnitine solution already develop mold after only 2 days, likely due to it being highly nutritious for microorganisms, and what is a potential solution for this problem?

What is the cause of the persistent separation during cooling of a cream containing 15 g Burow's solution, 15 g chlorobutanol hydrate, 800 mg zinc sulfate monohydrate, 480 mg methylprednisolone, 480 mg dexamethasone, 200 mg betamethasone dipropionate, 18 g Arlacel 83, 162 g white petrolatum, 15 g lactic acid, and 6 g salicylic acid with water up to 300 g, despite dissolving the chlorobutanol in the fatty phase, adding the Burow's solution and lactic acid to the aqueous phase, and finding that increasing the Arlacel concentration only provides a temporary improvement?

How can a pharmacist resolve the interaction between chlorhexidine digluconate solution and sodium lauryl sulfate to maintain emulsion stability in a prescription for ear drops containing 100 mg prednisolone, 50 mg chlorhexidine digluconate solution 20%, 4 g glycerin, 2 g cetyl alcohol, 100 mg sodium lauryl sulfate, and preserved water up to 20 ml?