The invention concerns a compound formed from a biologically degradable, water-soluble comb polymer based on a polyol backbone with side chains carrying amino groups, and, as a stabilizer, at least one negatively charged organic base, which can be a Lewis or Bronsted base, or its corresponding acid, which can be a Lewis or Bronsted acid, wherein the acid groups of the stabilizers are available in excess or deficiency in relation to the primary, secondary or tertiary amino groups or the basic groups are available in excess or deficiency in relation to the quaternary amino groups of the comb polymers, so that the colloidal particles feature a positive or negative zeta potential. Such colloidal particles are particularly suitable for pulmonary application of acidic or negatively charged pharmaceutically active ingredients.