Hyaluronidase (Hylenex): What It's Approved For, How It Differs From Vitrase, and Why It Lives in the Fridge

Hylenex is human recombinant hyaluronidase, 150 USP units/mL, sold as 1 mL single-dose vials, four to a carton, and it has to be refrigerated at 2°C to 8°C (Hylenex PI, rev. 11/2024). Vitrase is the ovine (sheep-derived) version at 200 USP units/mL (Vitrase label). Same enzyme class, different source, different strength, different excipients.

If you're buying hyaluronidase for a practice, those differences are the order. Here's what's on the labels.

What is Hylenex approved for?

Three things, per the label (Hylenex PI):

• "an adjuvant in subcutaneous fluid administration for achieving hydration"
• "an adjuvant to increase the dispersion and absorption of other injected drugs"
• "an adjunct in subcutaneous urography for improving resorption of radiopaque agents"

Vitrase lists the same three adjuvant uses (Vitrase label).

A lot of hyaluronidase is bought by aesthetic and dermatology practices. Anything outside those three labeled uses is a clinical decision for the prescriber, not something a supplier, or this article, gets to make for them.

Hylenex vs. Vitrase: what's actually different?

Sources: Hylenex PI; Vitrase label.

The strength difference matters on the shelf. 150 and 200 units/mL vials aren't interchangeable mL-for-mL, and protocols are usually written in units. Your clinicians pick the product. Purchasing makes sure the one that arrives is the one in the protocol.

What does the label warn about?

From the Hylenex label (Hylenex PI):

• Contraindicated with known hypersensitivity to hyaluronidase or any excipient.
• Not for intravenous use. The enzyme is rapidly inactivated.
• Don't inject into or around an infected or acutely inflamed area, because of the risk of spreading infection.
• Not for topical use on the cornea, and not for reducing swelling from bites or stings.
• Incompatible with furosemide, benzodiazepines, and phenytoin, and not to be used to enhance absorption of dopamine or alpha agonist drugs.

Why does storage matter so much?

Because it's a refrigerated product that a lot of practices don't use every day. The label says to store unopened vials at 2°C to 8°C and not to freeze them. It doesn't describe a room-temperature allowance (Hylenex PI).

What that means for purchasing:

• Ask how it ships. Cold-chain packaging, and what happens if it arrives warm.
• Check it in at the door. Put it in the drug fridge the day it arrives, not the next morning.
• It's single-dose. The label says to discard any unused portion. A vial that's been entered doesn't go back in the fridge for the next patient (CDC on single-dose vials). More in our single-dose vs. multiple-dose vials guide.
• Buy what you'll use before expiration. Ask what date ships.

Ordering checklist

• Order by product and NDC. Hylenex and Vitrase are different strengths, from different sources. If you're not sure what an NDC is, look it up.
• Note the excipient your clinicians care about: human albumin in Hylenex, lactose in Vitrase.
• Confirm cold-chain shipping before the first order.
• Refrigerate on receipt. Log it like your other fridge items.

Order Hylenex from Premier

Premier Pharma supplies licensed aesthetic, dermatology, and medical practices, clinics, and pharmacies, and every invoice lists the lot number and expiration date for each item. We carry Hylenex recombinant 150 USP units/mL, 4 × 1 mL vials. Open a free account. Credential review typically takes 1–2 business days.

Sources

• Halozyme. HYLENEX recombinant (hyaluronidase human injection) prescribing information. Rev. 11/2024.
• VITRASE (hyaluronidase injection) ovine prescribing information. Revised 1/2024. Via Drugs.com.
• Centers for Disease Control and Prevention. Preventing Unsafe Injection Practices.