Preformulation studies—The next advance in aluminum adjuvant-containing vaccines

The microenvironment pH is related to the surface charge of the adjuvant. [...]pretreatment of the adjuvant to adjust the surface charge to produce the microenvironment pH at which the adsorbed antigen is most stable is an important step in the formulation of vaccines. [...]the iep of aluminum phosphate adjuvant may also be varied between pH 9 to 4 by pretreatment with phosphate anion. [...]the iep of either adjuvant may be adjusted to produce enhanced or reduced electrostatic adsorption of the antigen, potentially leading to the optimization of vaccine potency as well as antigen stability during storage.