The present invention relates to compositions containing at least one cationic peptide active agent, at least one neutral structure forming amphiphile, at least one anionic structure forming amphiphile and optionally at least one solvent wherein the composition is in the form of a non-lamellar phase structure and/or forms a nonlamellar phase structure on exposure to body fluids. The invention also relates to methods for protecting peptides from enzymic degredation in vivo and to compositions in which the peptide active agent is so protected.