Quality study of aluminum hydroxide adjuvant for vaccine

Objective To establish quality standards in line with international standards for aluminum hydroxide adjuvant. Methods Ten batches of aluminum hydroxide adjuvant for vaccine were prepared and tested for appearance, sodium chloride content, osmolality, aluminum hydroxide content, and pH according to Chinese pharmacopoeia 2015 edition. Adjuvants were measured for solubility and endotoxin content, and subjected to identification test, sedimentation test, sterility test, bovine serum albumin (BSA) adsorption test as well as 13 inspection items of seven reference (chloride, sulfate, nitrate, ammonium salt, iron salt, arsenic salt, heavy metal) impurity tests according to European pharmacopoeia 8th ed (EP). The particle size, specific surface area, isoelectric point, viscosity and antigen adsorption rate were detected with reference to the Danish aluminum adjuvant. Test results were statistically analyzed to establish preliminary quality standards in accordance with EP. Results The adjuvants’ appearance, sterility, endotoxin content, solubility, identification test, sedimentation test, BSA adsorption test, and 7 impurity tests all qualified. The average sodium chloride content was 1.01%, average osmolality was 309 mOsmol/kg, average aluminum hydroxide content was 4.7 mg/ml, and average pH was 6.3 before and 5.8 after sterilization. The particle size (DV50) of adjuvant was <10 μm, average specific surface area was 1 386 m2/kg, isoelectric point was 10.3, and viscosity was 1.2 mPa·s. All test results were within respective quality control range. Conclusion Preliminary quality control standards for aluminum hydroxide adjuvant are established in accordance with EP. Key words: Vaccines; Aluminum hydroxide; Adjuvants, immunologic; Quality control