Vicario De La Torre, MartaHerrero Vanrell, María Del RocíoDíaz Valle, DavidBenítez Del Castillo Sánchez, José ManuelGegúndez Fernández, José AntonioGonzález-Cela Casamayor, Miriam AnaBurgos Blasco, BárbaraBrugnera, MarcoLópez Cano, José JavierYbañez García, LidiaPuebla García, Virginia2025-01-222025-01-222024-04-24Vicario-de-la-Torre, M.; Puebla-García, V.; Ybañez-García, L.; López-Cano, J.J.; González-Cela- Casamayor, M.A.; Brugnera, M.; Burgos-Blasco, B.; Díaz-Valle, D.; Gegúndez-Fernández, J.A.; Benítez-del-Castillo, J.M.; et al. Topical Insulin Eye Drops: Stability and Safety of Two Compounded Formulations for Treating Persistent Corneal Epithelial Defects. Pharmaceutics 2024, 16, 580. https://doi.org/10.3390/ pharmaceutics1605058010.3390/pharmaceutics16050580https://hdl.handle.net/20.500.14352/115534Compounded insulin eye drops were prepared at 1 IU/mL from commercially available subcutaneous insulin by dilution in saline solution or artificial tears. Physicochemical characterization and in vitro tolerance testing in human and conjunctival cells were followed by a 28-day short-term stability study under various conditions. The formulations were isotonic (280–300 mOsm/L), had a pH close to neutral (7–8), medium surface-tension values (<56 MN/m−1), and low (≈1 mPa·s) and medium (≈5 mPa·s) viscosities (compounded normal saline solution and artificial tear-based preparation, respectively). These values remained stable for 28 days under refrigeration. Microbiological stability was also excellent. Insulin potency remained in the 90–110% range in the compounded formulations containing normal saline solution when stored at 2–8 ◦C for 28 days, while it decreased in those based on artificial tears. Although both formulations were well tolerated in vitro, the compounded insulin diluted in a normal saline solution exhibited better cell tolerance. Preliminary data in humans showed that insulin in saline solution was an effective and safe treatment for persistent corneal epithelial defects. Compounded insulin eye drops diluted in normal saline solution could, therefore, constitute an emergent therapy for the treatment of persistent corneal epithelial defects.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal articlehttps://doi.org/10.3390/pharmaceutics16050580open access617.7615.4Topical insulinEye dropsCompounding stabilityIn vitro tolerancePersistent epithelial corneal defectsOftalmologíaTecnología farmaceútica32 Ciencias Médicas2407 Biología Celular