A practical approach to optimization and validation of a HPLC assay for analysis of polyribosyl-ribitol phosphate in complex combination vaccines

The use of multi-factor statistical experimental design methodology minimized the vaccine material and laboratory resources required for optimization and validation of an HPLC assay for quantitation of deploymerized and total PRP. Components of the assay selected for optimization were adjuvant dissolution, ultracentrifuge conditions including ultracentrifuge model, sample diluent, mobile phase and column oven temperature. Previous experience has shown these components of the assay to be most troublesome and therefore required optimization prior to validation. Specificity, linearity, precision, accuracy and ruggedness were confirmed through a validation of the optimized assay. The validation also established the assay to be stability indicating, by showing that changes to the integrity of the PRP-OMPC conjugate could be detected.