Alhydrogel® - aluminium hydroxide gel
Alhydrogel® is a sterilized aluminium hydroxide wet gel suspension which has been tested free of pyrogenicity. It tolerates re-autoclavation, but is destroyed if frozen.
When the pH is maintained at 5-7, which is normal during vaccine production, Alhydrogel® has a positive charge so they readily adsorb negatively charged antigens (e.g. proteins with acidic isoelectric points kept at neutral pH).
Alhydrogel® is available in three varieties:
- Alhydrogel® 1.3%
- Alhydrogel® 2%
- Alhydrogel® "85".
Alhydrogel® 2% was elected as the International Standard Preparation for aluminium hydroxide gels at an independant scientific workshop in Greece in 1988 and 1990 (ref. Stewart-Tull 1989 and 1991).
EP & BBS Specifications
Alhydrogel® products can be released for sale according to two different specifications - EP and BBS. As a standard procedure the product is sold with only one Certificate of Analysis (CoA) according to the EP specification. For an extra fee the customer may purchase the additional BBS certificate.
The European Pharmacopoeia (EP) specification was introduced following the 2004 launch of the Ph.Eur. monograph 1664 for aluminium hydroxide, hydrated, for adsorption. The EP specification is based on the test limits in monograph 1664. However, some tests are performed using methods which differs from the methods prescribed in Ph.Eur. and a pyrogenicity replaces the prescribed endotoxin test. Also note that Alhydrogel® cannot pass the prescribed identification test in monograph 1664.
The Brenntag Biosector Specification (BBS) is the original specification which most prominently includes the ash residue (Al2O3) analysis and a numeric analysis result of the protein adsorption capacity for human serum albumin (HSA) protein.of the protein adsorption capacity for human serum albumin (HSA) protein.
There is no difference in the production processes or procedures between Alhydrogel® products released with the EP or the BBS specification.
Alhydrogel® is produced in the following standard HDPE container types:
- 250 ml bottles equipped with a rubber stopper
- 5 kg cans with screw caps
- 25 kg cans with screw caps