large-volume parenteral
A large-volume parenteral, often shortened to LVP, is simply a big bag or bottle of sterile injectable fluid — by convention more than 100 millilitres in a single container, intended to be infused into a vein. If a small-volume parenteral is a single drink, an LVP is the whole jug.
LVPs are the workhorses of the hospital ward: bags of saline, glucose, balanced electrolyte solutions, dialysis and irrigation fluids, and the carrier bags into which other drugs are diluted. Because the patient receives so much liquid, an LVP must be isotonic with blood (or close to it), pyrogen-free, and absolutely sterile, and it must not contain antimicrobial preservatives — the volume is too large to allow the preservative levels needed for multi-dose products.
The no-preservative rule has a direct consequence: an LVP is a single-use, single-dose container. Once opened or spiked, any unused fluid is discarded, because there is nothing to stop microbes growing in it.
Manufacturing an LVP is unforgiving precisely because of its size. A single contaminated 1-litre bag delivers a far larger microbial or pyrogen load than a small ampoule would, so these products are usually terminally sterilized in their final container by steam wherever the formulation can withstand it.
A 1-litre bag of 5% dextrose used to maintain hydration overnight is a classic large-volume parenteral: isotonic, preservative-free and discarded if not finished.
Volume drives the rules: big bags must be isotonic, preservative-free and single-use.
The 100 mL boundary between large- and small-volume parenterals is a pharmacopoeial convention, not a sharp biological line, but it carries real rules: above it, no preservatives are allowed and single-dose containers are required.