Separation and quantification of a novel two-component vaccine adjuvant

Two reversed-phase HPLC methods were developed for the quantitative determination of the two components of the novel vaccine adjuvant IC31. The adjuvant consists of a mixture of a synthetic oligodeoxynucleotide (ODN) and an 11-mer cationic peptide. The negatively charged oligodeoxynucleotide and the positively charged peptide form a complex that has to be quantitatively dissociated for analysis. Dissociation of the complex was achieved with a basic heparin solution (1000 IU/ml) when analyzing the ODN, whereas 30% acetic acid was used for the determination of the peptide. Both methods are suitable for identification and quantification but also for stability indicating investigations.