1. Regular use of medication, except contraceptive, vitamin tablets, treatment with antimicrobial agents within the 3 months preceding the study, Use of antibiotics for 4 weeks prior to the study drug application or use of concomitant systemic or topical antibiotics, Systemic treatment with immunosuppressive drugs e.g. cyclosporine, azathioprine or oral corticosteroids within 4 weeks prior to baseline visit (Visit 2) .