IV fluids are salt water. Why are they so hard to make?

A shortage of intravenous (IV) fluids has been causing serious problems for hospitals worldwide.

While the Australian government this week announced it had secured 22 million additional bags for the next 6 months, it’s likely the shortage will still be affecting healthcare until at least the end of the year.

Several types of IV fluid are in short supply, but the most common one is saline – a solution of water and 0.9% sodium chloride, or table salt.

That’s all it’s made of – water and table salt. So given every kitchen has access to those materials, why is it so hard to make IV fluids?

“The answer is: it’s not hard to make salty water. It’s hard to make salty water to the standard required to use it as a medicine,” explains Professor Nial Wheate, a medicines scientist at Macquarie University.

As with any other medicine, IV fluids must meet extremely strict requirements to be considered safe for the  human body.

“If you’re buying a new car, you know that if there are going to be some niggles – maybe the wipers aren’t working properly, or there’s a wheel nut loose or something – you can just take it back to the dealer to have it fixed,” says Wheate.

“We can’t have that with medicines. Every medicine that comes off the production line has to be 100% perfect for what it has to do. We can’t have any leeway in the quality.

“Because of that, we have all these processes in place to make sure nothing can come out that’s not at the highest quality.”

Any facility making medicines must prove it’s meeting Good Manufacturing Practice, or GMP, principles. In Australia, the Therapeutic Goods Administration (TGA) regulates GMP compliance.

Getting GMP clearance is not easy.

“You can’t just build a facility. The TGA has to come in and inspect it, and do regular checks, and you have to keep records,” says Wheate.

Other countries have their own regulatory bodies with their own standards, and these also must be met to send medicines overseas.

Every ingredient involved in making a medicine must meet these high standards.

Supermarket-bought table salt is pure enough for cooking, but it’s not pure enough to inject into someone’s veins.

“It’ll be nowhere near the quality that we need to make medicines, because it’ll still have trace elements of other things, and we can’t have that – it might have other salts, it might have metals, it might have bacteria,” says Wheate.

This is true of other common IV fluid ingredients, like glucose and sodium lactate.

The IV fluid water must be ultra-sterile – a tricky thing to achieve, given water’s penchant for dissolving things.

The equipment used to make and transport IV fluids must also have GMP clearance.

“Even the plastic the IV bag is made out of has to be medical-grade plastic to make sure it doesn’t leach chemicals, or it doesn’t interact with the drugs that are going to be there,” says Wheate.

“You’ve got to have the team that’s capable of manufacturing it, you’ve got to have facilities that have been certified by the government, and you have to have the highest of high quality standards of your ingredients to go into all this. That’s what makes it complicated.”

This problem has occurred before with medicine shortages. In 2021, the global rush for mRNA vaccines was hampered not by the difficulty of making RNA – it’s a relatively simple process – but the difficulty of making it to medicinal standards, and the small number of GMP-certified facilities capable of doing it.

Another problem exacerbating this shortage is the number of facilities willing to make IV fluids.

“IV fluids are not super high profitable, or high return on investment, so I imagine a lot of companies don’t see it as valuable to invest in manufacturing IV fluids until you’ve got a shortage,” says Wheate.

Australia has just one local IV fluid manufacturer – Baxter’s plant in Sydney. The plant is already manufacturing at “record levels“, and is planning to expand its plant in the next few weeks to make more bags locally.

Wheate says that more local manufacturing of medicines would make Australia less susceptible to global shortages.

“We’re completely capable of doing it – it’s just that we’ve chosen not to because the companies say it’s not viable to make it here,” he says.

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