3PC-019 Abstract withdrawn

<h3>Background and Importance</h3> Calcinosis cutis is a rare, severe and chronic condition characterised by the deposition of insoluble calcium salts in the skin and subcutaneous tissue. These calcium salts cause reduced mobility, pain and chronic infections related to the development of ulcers. The preferred initial treatment is topical or intralesional sodium thiosulphate (STS). Intralesional administration is related to important adverse effects such infections and local pain, which make topical administration a preferred route. <h3>Aim and Objectives</h3> The aim was to develop and use a topical formulation based on STS to treat skin calcifications, promoting wound re-epithelialisation and facilitating the removal of calcium deposits. <h3>Material and Methods</h3> Based on existing literature a range of concentration of 10–25% STS formulations can be used. Zinc oxide was added due to its strong capacity to absorb exudates and skin secretions, as well as its wound healing and antiseptic properties. After testing various concentrations, the chosen formula was a 15% STS + 15% zinc oxide formulated in a water-in-oil (W/O) emulsion. According to the ‘<i>Guía de buenas prácticas de preparación de medicamentos en servicios de farmacia hospitalaria</i>’ <i>(Guide to good practices for preparing medications in hospital pharmacy services)</i> of the Spanish government, a beyond use date of 30 days at room temperature was established. <h3>Results</h3> The described formula was successfully used in six patients. The 15% of STS was enough to dissolve calcium deposits and consequently, to facilitate the manual deposits withdrawal by nursing. Additionally, the use of zinc oxide accelerated ulcer healing, allowing the treatment of the periwound skin, where non-visible small calcium deposits may be present. Moreover, this formula allows to space topical therapy every 48 hours, reducing potential local irritation caused by STS. <h3>Conclusion and Relevance</h3> Sodium thiosulphate 15% + zinc oxide 15% W/O emulsion is an useful treatment in calcinosis cutis, improving wound healing and reducing potential complications associated to this process. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest