Study Whose Purpose is to Find an Optimal Dose for the Treatment With AK 3012 in Patients With Actinic Keratosis

Inclusion Criteria: * Age: ≥ 18 years * Gender: male and female * Actinic Keratosis (Olsen grade I/II) * at least 5 actinic keratoses on the scalp, forehead, face, extremities, and/ or decollete * no treatment of the actinic keratoses within the previous 3 months before inclusion in the study * histologic confirmation of the diagnosis actinic keratosis by biopsy * good general condition * normal laboratory values (creatinine, urea, Glutamate-Oxalacetate Transaminase (GOT),Glutamate-Pyruvate Transaminase (GPT), gamma-glutamyl transferase (GGT), Lactate dehydrogenase (LDH)) and blood count at study start not higher than 1.5 x upper norm limit * Female patients must be tested negative for pregnancy before inclusion in the trial. During the trial, female patients have to apply a generally accepted form of birth control (i.e. oral estrogen- and gestagen containing contraceptives; estrogen containing skin plaster/ tape, hormone implant, hormone contraceptive coil, sterilisation; sexual abstinence) or being post-menopausal for at least 2 years. * Willing and able to participate in the screening and all trial specific procedures in compliance with the protocol * Signed written informed consent Exclusion Criteria: * Known allergy against nonsteroidal antiphlogistics and/ or against excipients of the investigational medicinal product * Presence of immunosuppression * Treatment with 5-fluorouracil, cyclosporine, retinoids, glycolic acid, imiquimod, trichloroacetic acid during the trial or 12 weeks before inclusion in the trial * Continuous treatment with nonsteroidal antiphlogistics with the exception of low-dose acetylsalicylic acid (100 mg) for inhibition of thrombocyte aggregation * Planned treatment with photodynamic therapy during participation in the trial * Pregnancy or lactation * Participation in another clinical trial within 3 months before inclusion in the current trial