Compositions and methods for preparing stabilized CSA compositions having reduced agglomeration and increased stability. The compositions have increased efficacy in killing microbes and reduced cytotoxicity to mammals. The compositions include a liquid carrier, micelles formed from an amphiphilic material, and CSA molecules encapsulated by the micelles. The CSA compositions can be formed by blending together a solvent or liquid carrier, a plurality of CSA molecules, and a micelle-forming agent and causing or allowing the micelle-forming agent to form micelles encapsulating at least a portion of the CSA molecules so that no more than 25% of the CSA molecules form agglomerates larger than 1 μm in size. The CSA compositions can be used to treat mammals, such as mammals suffering from microbial diseases or infections.