Abstract: Water substantially free of pyrogens and microorganisms that meets the requirements of United States Pharmacopoeia Standard USP XX Water for Injection is produced by processing drinking quality water through a filtration step adapted to remove organic contaminants and impurities that degrade downstream seperation membranes, a reverse osmosis step to remove dissolved solids, pyrogens, microorganisms and chemical contamination, a deionization step to further remove dissolved solids, and an ultrafiltration step to remove pyrogens. A sterile filter to remove microorganisms increases the water quality to USP XX Sterile Water for Injection. Means are provided to periodically remove accumulated chemical contaminants, pyrogens and microorganisms from the reverse osmosis apparatus, the deionization apparatus and the ultrafiltration apparatus. The sterile water can be admixed with a sterile concentrate composition to produce a sterile dilute solution that can be packaged under sterile conditions.

Abstract: The arrangement comprises a passageway for receiving liquid for intravenous administration (IV) or the like. A hydrophilic microporous membrane having a first pore size is disposed in the passageway at a first point so that all liquid passes through the microporous membrane at said first point. A microporous filter is disposed below the membrane in the passageway to filter all liquid passing through the passageway at the second point. The membrane has a bubble point high enough to withstand the expected head of liquid below it (the gravity head of the IV set). Should liquid from the source as it proceeds through the passageway from the microporous membrane to the filter be exhausted, then when air or gas reaches the membrane the flow of liquid is stopped because the upper, microporous membrane acts as an automatic shut-off valve. Air does not pass through the wet hydrophilic microporous membrane as long as the pressure does not exceed its bubble point.