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Alhydrogel General Information


Alhydrogel® is a sterilized aluminum hydroxide wet gel suspension which has been autoclaved in bulk and aseptically filled under LAF. It tolerates re-autoclavation, but is destroyed if frozen. When the pH is maintained at 6-8, 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 at neutral pH). Alhydrogel is available in three varieties: Alhydrogel 1.3%; Alhydrogel 2% and Alhydrogel “85″.

Alhydrogel is available in three standard versions:

1. Alhydrogel 1.3%

The product contains aluminum hydroxide, equivalent to an ash residue of 1.3 % AI2O3

2. Alhydrogel 2.0%

The product contains aluminum hydroxide, equivalent to an ash residue of 2.0 % AI2O3

3. Alhydrogel “85”

The product contains aluminum hydroxide, equivalent to an ash residue of 2.0 % AI2O3

(Alhydrogel 1.3% and 2.0% differ only in their concentration and in the directly derived parameters, such as the protein adsorption capacity per ml.).

With respect to final product analysis, Alhydrogel comes in two series:

A) One that complies with the original Brenntag Biosector specifications (“BBS-specification”).

B) One that is produced in accordance with the exact same recipe and in principle identical, but tested for compliance with the specifications given in the Ph. Eur. monograph 1664 (“EP specification”).

Standard packing sizes:

Alhydrogel® is supplied in high density PE-containers of 250 ml, 5 kg and 25 kg.

Typical batch sizes:

1800 – 2000 kgs. Those requiring additional information may request a download of product specification sheets and MSDS sheets for Brenntag Biosector's full product portfolio.

EP Monograph: By July 01, 2004 a monograph on aluminum hydroxide for use in adsorbed vaccines was launched by EP (monograph 1664).

Brenntag Biosector, now as a standard, tests the Alhydrogel series of ADJUVANTS provided by E.M. SERGEANT for final product specification compliance with that monograph. Below are the monograph specifications; note that Brenntag Biosector's compliance addresses the final product specifications. For some analyses Brenntag Biosector has chosen more modern assays than are referred to in the monograph, such as ion chromatography. In addition, there is a special issue on LAL-testing of aluminum hydroxide adsorbants.

About the EP endotoxin test:

The bacterial endotoxintest 2.6.14 prescribed in EP monograph 1664 is problematic with Alhydrogel, since the phosphate residues of LPS bind unspecifically to aluminum hydroxide. (LPS is used as assay positive control and standard curve.)

As a consequence a standard curve of LPS cannot be made in the presence of Alhydrogel.

Brenntag Biosector carries out the pyrogenicity test on the liquid phase of the product according to the EP 2.6.8 (i.v. injection into the ear veins of rabbits and measurement of rectal temperature) instead of the bacterial endotoxin test.