Leena ChularojanamontriChanisada WongpraparutNarumol Silpa-ArchaChayada ChaiyabutrChutipon PruksaeakananAnchalika KlinniyomSarawut JunnuChatchawan SrisawatFaculty of Medicine, Siriraj Hospital, Mahidol University2020-08-252020-08-252020-01-01Journal of Dermatological Treatment. (2020)14711753095466342-s2.0-85088875614https://repository.li.mahidol.ac.th/handle/20.500.14594/58224© 2020 Taylor & Francis Group, LLC. Background: Methotrexate (MTX) is a mainstay drug in the treatment of psoriatic and rheumatologic conditions. Subcutaneous MTX has become a feasible treatment alternative with the development of prefilled syringes or autoinjectors containing MTX solution that can be self-administered by the patient at home. However, MTX prefilled auto-injector pens are still not available in some countries. Objective: This study aimed to investigate the stability and sterility of 25 mg/mL MTX solution in a disposable plastic syringe over a 12-week period under light protection at temperatures of 4 °C, 25 °C, and 37 °C. Methods: This study was conducted during November 2019 to February 2020 at the Faculty of Medicine Siriraj Hospital, Mahidol University. Stability was evaluated using ultra-high-performance liquid chromatography technique, and sterility was assessed by cultures for bacterial and fungal contamination. Results: Our results revealed that patient-ready syringes containing 25 mg/mL MTX solution can be prepared in advance and kept for up to 12 weeks under light protection, and they can be kept at temperatures ranging from 4 to 37 °C. Conclusion: This system for delivering MTX to patients that are refractory to or intolerant of oral MTX via a self-administered pre-filled syringe is both efficient and easy to implement in care settings where commercially alternatives are not yet available.Mahidol UniversityMedicineArticleSCOPUS10.1080/09546634.2020.1800570