Capellion is a Phase 2, multicenter, randomized, double-masked, vehicle-controlled pilot trial in up to 32 adult Participants with persistent corneal epithelial defects (PCED) that have not completely healed after at least 10 days of standard-of-care treatment. Participants will be randomized 1:1 to receive TP-06 2.0% or Vehicle four times daily for 8 weeks, along with protocol-required background therapy, followed by a 2-week post-treatment period. The trial will evaluate the efficacy and safety of TP-06, including complete corneal healing, the timing and extent of healing, visual acuity, and changes in corneal thickness.