2.7. Pharmacodynamic Evaluation

Twenty-four Balb/c mice were randomized into four groups for a single dose of test formulations (Formulation blank, Formulation containing 5% drug, Commercial product, and untreated). A 10 μL of 0.8% croton oil (inflammatory inducer) in acetone was painted onto the inner surface of the left ear of each mouse to induce rosacea disease model. Fifteen mins after the induction, 50 μL of the different formulations (equal to 2.5 mg drug) were topically applied to the left ear. At 0, 4, 8 and 24 h, the thickness of each ear, near the top of the ear distal to the cartilaginous ridges, was measured. The change (swelling %) in ear thickness of the left ear from the right ear was taken as an edema index [21,22].