Vericiguat is intended to be used for the treatment of cardiovascular diseases, especially heart failure. Heart failure also occurs in children. Therefore, a study testing vericiguat in the treatment of heart failure in paediatric patients is planned under the paediatric investigational plan (PIP). In order to administer vericiguat to children, a vericiguat paediatric formulation is needed. This paediatric formulation is characterized in this study prior to its use in paediatric patients.