Using medication with animal derivatives

Is it permissible to buy and use a medicated cream for acne that contains animal derived ingredients? I am not sure what animal they are derived from. This cream appears to have worked very efficiently for many people with acne however there is no guarantee that it will work for me as well, but there is a very high likelihood that it will. I will simple put it on my acne then wash it off a few minutes later. Nothing else has worked for me and finding halal creams are difficult as it is. Is this permissible?