Ointment containing spray freeze-dried metronidazole effective against rosacea

Rosacea is a chronic, inflammatory skin disease that affects about 10% of the population. Metronidazole-containing ointments are typically recommended for the daily treatment of symptoms. For increasing bioavailability and effectiveness, it is needed to reduce the particle size. Therefore, micronized metronidazole was prepared by spray freeze-drying (SFD) method, then its most important features were examined such as morphology, crystallinity and particle size. The anti-inflammatory effect of the as-prepared agent was tested on a mouse model of rosacea for effectiveness against oedema and redness of the ears, and it was compared to a reference cream.