Ultra Violet B Radiation (UVR) Study of Strontium Chloride Hexahydrate Hydrocortisone

Inclusion Criteria: * Signed and dated informed consent prior to any study-mandated procedure * Subjects in good health as determined by the Investigator * Willing and able to comply with study requirements * Age ≥ 18 * Fitzpatrick skin types I, II, or III * Willing to avoid sun exposure, tanning lamps and use of any topical products on the test areas during the study * Willing not to wash test areas during treatment period * Willing to abstain from sauna, exposure to extreme cold or major physical activities during the treatment period of the study * For females, subjects of childbearing potential (including peri-menopausal women who have had a menstrual period within 1 year) must be using appropriate birth control (defined as a method which results in a low failure rate, i.e., less than 1% per year when used consistently and correctly, such as implants, injectables, some intrauterine contraceptive devices (IUDs), sexual abstinence, or a vasectomized partner). Oral contraceptive medications are allowed in this study. Female subjects, who are surgically sterile (bilateral tubal ligation, bilateral oophorectomy or hysterectomy) are also allowed for participation Exclusion Criteria: General * Planned treatment or treatment with another investigational drug within 30 days prior to randomization. * Subjects who are inmates of psychiatric wards, prisons, or other state institutions * Investigator or any other team member involved directly or indirectly in the conduct of the clinical study * Pregnancy or lactation * Any known factor or disease that might interfere with treatment compliance, study conduct or interpretation of the results such as drug or alcohol dependence or psychiatric disease. Medical History * Malignancy within the past 2 years with the exception of in situ removal of basal cell carcinoma * Known hypersensitivity or allergy (including photoallergy) to hydrocortisone, strontium chloride hexahydrate, glycofurol, dimethylsulphoxide (DMSO), ethanol, propylene glycol, glycerol, hypomellose, sodium edentate, sodium hydroxide, citric acid monohydrate and metagin * History of photosensitivity disease * Sunburn, excessive tan, uneven skin tones or blemishes of the test areas * Pain conditions which might interfere with pain rating during the study, e.g. neuropathic pain * Open wounds, infection, inflammation or other dermal diseases of the intended application areas * ALT or AST ≥ 5 times the ULN * Glomerulary filtration rate \< 30 ml/min Medication History * Systemic or topical drugs that might affect responses to UVR or interfere with responses to IMP including corticosteroids, thiazides, tetracyclines and NSAIDs must be washed out with 5 times half-life time prior to randomization to treatment * Drugs with potential dermatologic adverse events defined by the respective summary of product characteristics (e.g. tetracyclines, gyrase inhibitors) must be washed out with 5 times half-life time prior to randomization to treatment