Question
Posted on: March 6 2013Flakes in a benzoyl peroxide-Erythromycingel. Erythromycin 1g benzoyl peroxide 2.5 G Carbopol gel ad 50g
Benzoyl peroxide is rubbed into mortar with chloroform to homogenous powder. Erythromycin with propylene glycol. Both are now mixed together and one gets a nicely homogeneous mixture. When adding the gel, flakes emerge. What went wrong?
Answer
In its second part, the TMF will describe such gel. After a lot of research, I have come to the conclusion that any additional solvent should be avoided. So both powders rub each other into a fine powder and then with an equal volume of Carbopolgel. Afterwards can be further diluted. The flakes are derived from the incompatibility between erythromycin and Carbopol. Of course, I should strongly recommend that you treat the gel with the ointment grinder.