Journal of Vaccines & Vaccination

Abstract

Effect of Storage Temperature on the Quality Stability of Nanoparticle Aluminum Hydroxide Adjuvant

Xifei Yang, Feiwei Zhang*

The aluminum hydroxide adjuvant exhibits a Poorly Crystalline Boehmite (PCB) structure, which is influenced by storage conditions. In this research, we comprehensively disclosed the alterations in the crystal structure, combination conventional quality indicators of the adjuvant during storage under different temperature conditions. Three batches of aluminum hydroxide adjuvants were respectively stored at 2-8°C, 18-25°C, and 37°C for 6 months. We detected the X-ray diffraction, pH, Isoelectric point (pI), adsorption rate, and average particle size of the adjuvants. X-ray diffraction revealed that the aluminum hydroxide adjuvants were PCB. After being stored at 37°C for 1 months, new diffraction peaks emerged at 18.2° 2θ in the diffract grams of the adjuvants, and the peak intensity increased along with the extension of the storage time. Meanwhile, the decreases of pI and pH were the greatest, being 0.78 and 1.33 respectively. When the adjuvant was stored at 2-8°C and 18-25°C for 6 months, only weak diffraction peaks at 18.2° 2θ were observed, showing that the crystal structure was stable or began to change. The decreases of pI and pH were the minimum, being 0.43 and 0.80 respectively. The nanoparticle aluminum hydroxide adjuvant retains a high level of adsorption capacity throughout the storage process, making it an extraordinary vaccine adsorbent. However, the increase in storage temperature will accelerate the aging of the adjuvant and the formation of highly crystalline gibbsite or bayerite, which is detrimental to the quality stability of the adjuvant.

Published Date: 2025-10-15; Received Date: 2024-09-24