Efficacy and Safety of ZKARE® Gel and Its Accessory ZKAPI® in the Treatment of Chronic Ulcers.

Inclusion Criteria: * Adult patients (≥18 years). * Presence of at least one chronic hard-to-heal ulcer, including any of the following etiologies: Grade II, III or IV pressure ulcers; neuropathic diabetic foot ulcers (grade I, II or III), Wagner Grade I-III or Texas 0, I, II, III / Stage B; class C6/C6r venous leg ulcers measured with CEAP scale ; neuro-ischaemic ulcers with adequate distal perfusion (ABI/ITB ≥ 0.7-0.89; mild PAD); mixed-etiology venous ulcers and any chronic lower-limb lesion with palpable distal pulses. * Ulcer size between 1 cm² and 100 cm². * Ability and willingness to comply with all study visits and procedures according to the clinical protocol. * Ability to understand and sign the informed consent, obtained before performing any protocol-specific procedures. Exclusion Criteria: * Ulcers of etiologies not listed in the inclusion criteria. * Ischaemic, neoplastic or atypical ulcers. * Severe comorbidities judged to compromise safety or study compliance, including: severe malnutrition, palliative/terminal status, severe anemia, decompensated heart failure, chronic kidney disease stage III/IV or in dialysis. * Ulcers with moderate-severe or severe infection per PEDIS-IDSA infection grading scale. * Known allergy or sensitivity to any component of the investigational product. * Any condition that, in the investigator's opinion, may compromise patient safety or adherence to the protocol. * Pregnancy or planned breastfeeding.