Question
Posted on: August 20 2016In the preparation of a cream with Levomenthol 2%, erythromycin 4% AD 100 gram Cetomacrogol cream, however, I received twice a formation of large clubbers
Can anyone explain this? It seems that the problem mainly lies with the Levomenthol. However, from the properties, I cannot explain any incompatibility between the ointment base and the erythromycin. Does anyone know council? I have to add that I solved the menthol in a bit of ether and then rubbed this solution with a spatula point Cetomacrogol cream. Then geometrically erythromycin and Cetomacrogol Cream added. At the beginning no problem after a few minutes a slice. I also used the ointment grinder.
Answer
Indeed between Levomenthol and erythromycin can not occur incompatibility but does between ether and Cetomacrogol cream. I think it is better to solve the menthol in a minimal amount of a solution ether-alcohol 1:1 and rub this solution dry with lactose or mannitol. After evaporating the organic solvents, the powder is rubbed with a small fraction of cetomacrogol cream to homogenous. This mixture can then be further diluted with the remaining amount of Cetomacrogol cream. Due to the presence of erythromycin, unbuffered Cetomacrogol cream is used here.