PRODUCT SEARCH
Enquiries
If you have any questions about products featured on this site, or on products that you cannot find on this site, please contact us and we will be happy to assist you in any way that we can. We have a team of technical sales specialists who are waiting to hear from you!
Contact UsHome > Life Science Solutions > Purification and Downstream Processing > PurifiDE® XG
PurifiDE® XG
Purified Siliceous Earth (DE) USP-NF Bulk Pharmaceutical Excipient Filter Aids for pharmaceutical and Biologics uses.
The PurifiDE® range of Purified USP-NF Diatomaceous Earth Filter Aids called "Bulk Pharmaceutical Excipient Filter Aid" (BPEFA) have been created for use (21 CFR Part 210.3) in the filtering of human and animal drug products via chemical or biological routes. PurifiDE® XG BPEFAs are manufactured in accordance with cGMP Practices for Bulk Pharmaceutical Excipients (USP40-NF35 <1078>).

Typical uses include:
Fractionation of blood plasma proteins at manufacturing scale
Filtration of active pharmaceutical ingredients (APIs) that have been dissolved in either aqueous or organic liquids
Rapid clarification of cell culture media or cell lysates including soluble recombinant biopharmaceuticals without centrifugation
Filtration of salt solutions and buffers, amino acids, and peptides used in pharmaceutical manufacturing.
Manufacturing Process
PurifiDE® XG Purified Siliceous Earth USP-NF BPEFAs is produced in the USA from unique low-density DE ores. Following calcination, the DE is purified further in a closed manufacturing facility using certified machines, validated procedures, batch records, and detailed documentation using a patented cGMP compliant method. They included strictly regulated manufacturing processes such as in-process QC testing and final product QC testing. Also, in highly acidic extracts, ICH Q3D Class 1, Class 2A, and some Class 3 elemental impurities are reduced to trace amounts by these manufacturing processes (Table 1).
ICH Q3D elemental impurity for risk assessment consideration |
ICH Q3D Classification |
PurifiDE XG-3 USP-NF |
PurifiDE XG-12 USP-NF |
Arsenic (ppm) |
1 |
<0.025 |
<0.025 |
Cadmium (ppm) |
1 |
<0.025 |
<0.025 |
Mercury (ppm) |
1 |
<0.0025 |
<0.0025 |
Lead (ppm) |
1 |
<0.025 |
<0.035 |
Cobalt (ppm) |
2A |
<0.025 |
<0.025 |
Molybdenum (ppm) |
2A |
<0.025 |
<0.025 |
Selenium (ppm) |
2A |
<0.125 |
<0.125 |
Vanadium (ppm) |
2A |
0.065 |
<0.025 |
Copper (ppm) |
3 |
0.125 |
0.15 |
Lithium (ppm) |
3 |
<2.5 |
<2.5 |
Nickel (ppm) |
3 |
0.03 |
0.08 |
Tin (ppm) |
3 |
<2.5 |
<2.5 |
Antimony (ppm) |
3 |
<0.025 |
<0.025 |
Table 1. Typical levels of soluble elements detected by ICP-MS in filtrates after incubation of PurifiDE XG-3 and XG-12 in 0.1M HCI for 1 hr.


Available filtration grades of PurifiDE®
PurifiDE Grade |
Permeability range (mDarcy) |
XG-1 |
50 – 140 |
XG-3 |
200 – 500 |
XG-12 |
800 - 1400 |
Quality Control
PurifiDE® XG Purified Siliceous Earth USP-NF BPEFAs undergo stringent quality control testing to ensure that any manufacturing lot of PurifiDE® XG matches or exceeds the USP 40-NF 35 Monograph on Purified Siliceous Earth’s specifications. Three separate samples from each lot (450 kgs) are tested in the cGMP compliant QC laboratory using certified analytical instruments and validated or verified compendial and non-compendial tests. Tables 2A and 2B Tests demonstrate the tests specified on the Certificate of Analysis for PurifiDE® XG Purified Siliceous Earth USP-NF BPEFAs. Please contact us for copies of Certificates of Analysis.
Compendial Parameters |
Limits |
Loss on Ignition |
NMT 2.0 % |
Leachable Arsenic |
NMT 10 (mg/kg) |
Leachable Lead (µg/g) |
NMT 10 (mg/kg) |
Limit of Non-Siliceous Substances |
NMT 50 (mg in 200 mg) |
Loss on Drying |
NMT 0.5 % |
Acid-Soluble Substances (%) |
NMT 2 |
Water-Soluble Substances (%) |
NMT 0.2 |
Table 2A. Tests and limits for compendial tests shown on the certificates of analysis for PurifiDE XG USP-NF Purified Siliceous Earth (Bulk Pharmaceutical Excipient Filter Aid GMPs).
Non-Compendial Parameters |
PurifiDE XG-12 |
PurifiDE XG-3 |
Leachable Iron (µg/g) |
NMT 10 |
NMT 10 |
Permeability (Darcy) |
0.8 – 1.4 |
0.2 – 0.5 |
Conductivity (µS/cm) |
NMT 20 |
NMT 20 |
Centrifuge Wet Density (g/ml) |
NMT 0.37 (NMT 23 lbs./ft3) |
NMT 0.37 (NMT 23 lbs./ft3) |
Table 2B. Parameters and limits for non-compendial tests validated or verified by EP Minerals, which are reported on the PurifiDE XG USP-NF Purified Siliceous Earth (Bulk Pharmaceutical Excipient Filter Aid GMPs) Certificates of Analysis.

Figure 1. A 208-litre fibre drum containing 45.36Kg PurifiDE XG-12 USP-NF Purified Siliceous Earth (Bulk Pharmaceutical Excipient Filter Aid GMPs). The top cover is locked in place with a steel band and a tamper-evident seal. A food-grade plastic bag holds the product in the drum.

Figure 2. Example of a packaging label applied to paper bags containing PurifiDE XG-12 Purified Siliceous Earth USP-NF . The label shows product grade, permeability range, the lot number, manufacturing month and year, and other details.
Samples and evaluations
Please get in touch with us to discuss your application, technical support, samples and processing technologies.
Downloads:
- Download Safety Data Sheet
- Download XG 3 Specifications
- Download XG 12 Specifications