ADJUVANT STABILITY

Aluminium hydroxide adjuvant (e.g. AlhydrogelTM) can be easily damaged by inadvertent freezing which results in agglomeration of the adjuvant rendering the vaccine useless. Stabilitech treatments can prevent this damage from occurring which would mean that adjuvanted vaccines could be stored cryogenically. In addition, Stabilitech has also developed methods enabling the lyophilization of adjuvanted vaccines without losing the structure or function of the adjuvant.

The most common deficiencies in the cold chain, reported from developed countries, are temperature excursions due to either high temperatures during storage or transport exposure of adsorbed vaccine to freezing.

Freezing of adsorbed vaccine causes the aluminium component to precipitate, and has a devastatingly negative impact upon the vaccine’s potency.

Therm-SB technology is able to protect alum adjuvanted vaccine in two ways:

  1. the protein component is protected from temperature variations and
  2. the adjuvant is prevented from aggregation if inadvertent freezing occurs (as shown in the figure above).

Lyophilized alum – Unique to Therm-SB, the stability conferred upon the adjuvant also enables alum adjuvanted vaccines to be lyophilized with the surprising finding that upon reconstitution the gel reforms immediately and the vaccine is ready for injection.

 

 

Fig: Alhydrogel particle size analysis following freeze-thaw