Quality control methods for oil-in-water emulsions containing squalene
Measurements of the squalene content in oil-in-water emulsions can be used as a way of checking for problems during production. In particular, it has been found that a drop in squalene content can indicate that filtration problems occurred. Testing the squalene content in the final lots is easier than investigating the characteristics of the filter, and so a squalene assay simplifies the quality control of oil-in-water emulsions.
1. A method for controlling the quality of an oil-in-water emulsion adjuvant, which comprises squalene and an aqueous carrier as components, by determining whether said oil-in-water adjuvant has an acceptable level of squalene, said method comprises:
preparing the oil-in-water emulsion by placing the components of the oil-in-water emulsion in a microfluidizer and microfluidizing the components to form a microfluidized mixture;
(ii) filtering the microfluidized mixture through a filter to provide the oil-in-water emulsion and forming the oil-in-water adjuvant;
(iii) measuring the actual squalene content in said oil-in-water emulsion adjuvant;
(iv) comparing the actual squalene content in said oil-in-water emulsion adjuvant with a standard squalene content;
(v) rejecting said oil-in-water emulsion adjuvant if the actual squalene content of said oil-in-water emulsion adjuvant differs from the standard squalene content by more than plus or minus 10%.
2. The method according to claim 1 , wherein the components of the oil-in-water emulsion further comprise a surfactant.
3. The method according to claim 1 wherein the oil-in-water emulsion in the oil-in-water adjuvant is a submicron emulsion.
4. The method according to claim 3 , wherein the components of oil-in-water emulsion adjuvant further comprise polyoxyethylenesorbitan monooleate and sorbitan trioleate.
5. The method according to claim 1 , wherein the components of the oil-in water emulsion further comprises a tocopherol and polyoxyethylenesorbitan monooleate.
6. The method of claim 1 , wherein the components of the emulsion in the oil-in water emulsion further comprises a tocopherol and t-octylphenoxypolyethoxyethanol.
7. The method of claim 1 , wherein the components of the oil-in water emulsion further comprises a polyoxyethylene alkyl ether hydrophilic nonionic surfactant and a hydrophobic nonionic surfactant.
8. The method of claim 1 , wherein if the oil-in-water emulsion adjuvant has an acceptable level of squalene content, the method further comprises the further step of (v) combining the oil-in-water adjuvant with an antigen.
9. The method of claim 8 , wherein the antigen is an influenza antigen.
10. The method of claim 1 , wherein the standard squalene content is a squalene concentration between 2% and 8% by volume.
11. The method of claim 10 , wherein the standard squalene content is a squalene concentration between 4% and 6% by volume.