Hereditary ichthyoses are rare genetic diseases (13.3 cases per million in Europe) that appear at birth or in early childhood, causing scaling, skin thickening, dryness, itching, and pain. Approximately half of the patients, especially those with Autosomal Recessive Congenital Ichthyosis (ARCI), present a defect in the synthesis of CerEOS, a ceramide essential for the epidermal barrier. Current treatments are only symptomatic and not very effective. The LIPARCI II project develops a lipid replacement therapy based on CerEOS encapsulated in biomimetic nanoparticles, capable of restoring the skin barrier in preclinical ARCI models. Additionally, LIPARCI II includes a phase 0 clinical trial to evaluate bioavailability, will advance large-scale production, and will develop new models and formulations to expand the number of beneficiary patients.