Dapsone for topical use in extemporaneous preparations

Background: The sulfone dapsone has an established role in systemic therapy. Its pharmacological and toxicological properties are well known. Topically, dapsone is used in a gel formulation for the treatment of acne vulgaris. In addition, there have been individual case reports on the efficacy of topical dapsone preparations in the treatment of various neutrophilic dermatoses. To date, no finished medicinal product for topical use has been available in Germany. Material and methods: Against this background, we set out to develop extemporaneous preparations containing dapsone (5 %) that meet the quality requirements of the European Pharmacopoeia as well as the manufacturing requirements of the German Ordinance on the Operation of Pharmacies (ApBetrO). These formulations included the incorporation of dapsone in a hydrophobic cream base ("hydrophobe Basiscreme DAC") as well as in methylprednisolone aceponate 0.1 % ointment (alternatively, in the latter's cream base without active ingredient). Results: Tests aimed at investigating the physical, chemical, and microbiological stability of these formulations showed them to meet the aforementioned quality requirements. Conclusion: The extemporaneous formulations presented herein broaden the therapeutic options for topical treatment, in particular for patients with chronic inflammatory dermatoses associated with a neutrophilic pathogenesis.