Question
Posted on: March 6 2013Problem with ear drops: polymyxin B 100000E chloramphenicol 50mg hydrocortisone 50mg propylene glycol 5mg Aqua 5ml
Polymyxine dissolves perfectly in water; Chloramphenicol and hydrocortisone in propylene glycol from the moment I do the water at the propylene glycol I get a precipitation. Presumably the chloramphenicol strikes down but when I leave that eriut I see that the hydrocortisone also precipitates back. What can I do about this?
Answer
I suspect these drops are destined for the outer ear and so I would say take pure propylene glycol but probably polymyxin is not soluble in PG. So you can not do other than deliver the drops with a precipitate. And a label "shake before Use". Sometimes, ear doctors want a powder deposit in the external auditory canal.