The thickness of a liquid film between the remnant of a soluble nucleus of condensation and surrounding vapor-gas medium is calculated with taking into account the film disjoining pressure. The thickness corresponds to the maximum of the chemical potential of a substance condensing in droplet out of vapor. The maximum value of this potential itself is found over the range of incomplete dissolution of a nucleus. It is established the value of vapor chemical potential which determines the threshold for barrierless condensation on soluble nuclei. This threshold is found as necessary not only over the range of complete nucleus dissolution but also over the range of incomplete nucleus dissolution.