Comparison of Efficacy and Safety of Azelaic Acid 15% Gel With Its Vehicle in Subjects With Mild to Moderate Acne

Inclusion Criteria: To be included in the study you MUST have: * Predominantly facial localization of acne * Mild to moderate acne vulgaris characterized by the presence of both inflammatory papules and/or pustules, and comedones (whiteheads/blackheads), and of a severity suitable for treatment with topical single therapy. * a minimum of ten and a maximum of fifty inflammatory papules and/or pustules in the facial area and * 10 to 100 comedones in the facial area * no more than 3 small nodules (approx. 5 mm in diameter) in the facial area * Male and female patients * Age greater or equal to 12 years * Ability and willingness to accept and comply with the administration of the investigational drugs over 12 weeks and to comply with the required medical examinations (signed informed consent). Exclusion Criteria: To be included in the study you MUST NOT have: * Localization of acne predominantly on the chest and/or the back or confined to the chest and/or the back * Sandpaper acne with hundreds of small facial comedones * Moderate or severe acne requiring systemic therapy * Multitude of small nodules and/or multiple large nodules, cysts, polyporous comedones, draining sinuses e.g. nodulocystic/conglobate acne * Other skin conditions that might interfere with acne diagnosis and/or evaluation (such as facial psoriasis, seborrheic dermatitis, perioral dermatitis and papulopustular rosacea) * Anticipated or scheduled hospitalization, e.g. for surgery, during the study * Female p…