Abstract
The effect of varying the pH and ionic strength on endotoxin removal (depyrogenation) from Water for Injections (WFI) was investigated. Studies using submicron filters showed that endotoxin aggregation and filter retention increased with increasing molarity and decreasing pH. Using a Sartorius 0.01 μm filter, greater than 98% endotoxin retention could be achieved with 10 endotoxin units (EU)/ml bulk solution, and greater than 97% endotoxin retention with the 500 EU/ml bulk solution. Depyrogenation of active and placebo solutions of the radiopaque, Iohexol (350 mgl/ml), using ultrafilters of varying nominal molecular weight limit (NMWL 10,000–300,000) and a Pall Posidyne® 0.2 μm filter was also investigated. Results with the ultrafilters showed that it was possible to increase the molecular weight cut-off of an ultrafilter from 10,000 to 100,000, without affecting the efficiency of endotoxin removal, thereby increasing flow rate and reducing filtration time. The Posidyne® filter was able to depyrogenate Iohexol active and placebo product. The use of submicron filtration in place of ultrafiltration would provide significant cost benefits in terms of filtration time and equipment costs, and they have been shown to be capable of efficient depyrogenation of these pharmaceutical products.
- Received December 11, 1992.
- Accepted April 26, 1993.
- Copyright © Parenteral Drug Association. All rights reserved.
PDA members receive access to all articles published in the current year and previous volume year. Institutional subscribers received access to all content. Log in below to receive access to this article if you are either of these.
If you are neither or you are a PDA member trying to access an article outside of your membership license, then you must purchase access to this article (below). If you do not have a username or password for JPST, you will be required to create an account prior to purchasing.
Full issue PDFs are for PDA members only.
Note to pda.org users
The PDA and PDA bookstore websites (www.pda.org and www.pda.org/bookstore) are separate websites from the PDA JPST website. When you first join PDA, your initial UserID and Password are sent to HighWirePress to create your PDA JPST account. Subsequent UserrID and Password changes required at the PDA websites will not pass on to PDA JPST and vice versa. If you forget your PDA JPST UserID and/or Password, you can request help to retrieve UserID and reset Password below.