Quick facts
- An eye drop is a drug, not a device, in both Canada and the United States.
- In the United States an ophthalmic demulcent can be marketed under an OTC monograph at 21 CFR 349.12 without a new drug application.
- Canada has no OTC monograph system for eye drops; a product needs a DIN under the Food and Drug Regulations or an NPN under the Natural Health Products Regulations.
- A preservative-free drop is usually a unit-dose vial; a preserved drop is usually a multi-dose bottle with a preservative such as benzalkonium chloride.
- The preservative is what changes the packaging, the shelf life after opening, and often the cost per millilitre — not the active ingredient.
- The regulation text cited here is current to 2026-09-21 and was last amended on 2026-06-17.
A preservative-free eye drop is the same lubricant as its preserved version without the antimicrobial that keeps a multi-dose bottle from going off. The active ingredient does not change; the container, the route to market and the record do. On one side of the border the drop can be sold under a published monograph; on the other every drop is a licensed drug with its own number.
What does a preservative-free eye drop actually contain?
The active ingredient is a demulcent, an emollient or an astringent, and the preservative is simply absent.
The United States groups these ingredients into three OTC monographs: 21 CFR 349.12 for ophthalmic demulcents, 21 CFR 349.14 for ophthalmic emollients, and 21 CFR 349.10 for ophthalmic astringents. Each lists permitted actives and permitted concentrations. A product that stays inside the monograph and makes only the permitted claims can be placed on the market without a product-specific approval.
A preservative-free product cannot lean on the same convenience. Once the bottle is unsealed, a preserved multi-dose container is protected between uses; a unit-dose vial is meant to be used and discarded. That single design decision is what makes the preservative-free format the one pharmacies and clinics store, dispense and bill differently from a bottle.
How does Canada and the United States each regulate a preservative-free eye drop?
The drop is a drug in both countries, but the door it comes through is not the same.
| Item | Canada | United States |
|---|---|---|
| Legal category | Drug or natural health product | Drug |
| Market entry | DIN or NPN, product by product | OTC monograph, or an approved application |
| Marketing without a product number | Not permitted | Permitted inside the monograph |
| Governing text | Food and Drug Regulations / NHP Regulations | 21 CFR 349.12 |
| Register | Drug Product Database | openFDA drug label API |
In Canada a manufacturer who wants to sell an eye drop must hold a Drug Identification Number for a drug, or a Natural Product Number where the product is regulated as a natural health product. Both are product-specific. A Canadian buyer who wants to confirm that a drop is lawfully marketable looks for that number on the label, not for a monograph citation.
This is the point most often missed when a Canadian clinic compares a US catalogue with its own. The US price sheet may not carry a product number at all, because the monograph does not require one. Absence of a number is not a defect in the United States and is not evidence of a defect anywhere; it reflects a different route.
Do Canada and the United States treat the preservative the same way?
They treat the preservative as a formulation choice, and the difference that matters is packaging rather than permission.
| Format | Preservative | Typical use window | Storage note |
|---|---|---|---|
| Multi-dose bottle | Present (for example benzalkonium chloride) | Defined by the label once opened | Kept sealed between uses |
| Unit-dose vial | None | Single use, then discarded | No communal bottle |
| Unit-dose strip | None | Single use, then discarded | No communal bottle |
A preservative is an antimicrobial. Its job is to keep a container that is opened many times from becoming a source of contamination. Remove it and the container must change: the drop is sealed into a vial that is used once. That is why the preservative-free format exists at all, and why it appears most often where a preserved drop would be used many times a day over a long period.
For a clinic, the practical consequence is storage and record-keeping. A multi-dose bottle has an in-use period; a unit-dose vial does not, because it is not reused. Whoever stocks the room has to keep those two rules apart, and the easiest way to do that is to keep the two formats on separate shelf positions with the in-use rule written on the preserved one.
Why does a preservative-free drop cost more per millilitre than a preserved bottle?
Because the unit-dose container costs more to make than a bottle, and the price reflects the packaging, not a difference in the active ingredient.
The active ingredient in a unit-dose vial and the same active in a multi-dose bottle can be identical. What is not identical is the fill-and-seal line, the number of containers per dose, and the fact that a vial is discarded after one use. A 10 mL bottle delivers many doses from one container; ten 0.4 mL vials deliver the same volume from ten containers. The cost sits in the containers.
This is why the preservative-free format is chosen deliberately rather than by default. A clinician selects it when the exposure profile or the frequency of use makes the packaging worth the difference. It is a formulary decision, and it belongs in the same conversation as any other drug-selection choice.
Which consumables does an eye clinic restock alongside its drops?
A drop is one item on a bench that also runs on reusable and single-use supplies. For a warm-compress routine the USB heated eye mask with three temperature settings is the reusable item that sits with the drop regimen. Around the examination itself, the sterile graduated 90 mL specimen cups carry samples to the bench and the 120 mL sterile screw-cap container holds anything that has to be kept before it is processed. Where a clinic also runs its own sterilisation cycle, the sterilization monitoring collection pairs with the 24-hour monitoring five-pack trial. Clinics and multi-site groups buying at case level use the wholesale ordering page, and the B2B wholesale collection lists the lines held for institutional buyers. Reselling? become a distributor.
Do Canada and the United States require the same information on the label?
Not in the same shape, and the difference is the product number again.
In Canada the label of a drug must carry its Drug Identification Number, and the label of a natural health product must carry its Natural Product Number. The number is also recorded in the Drug Product Database published by Health Canada, so a buyer, a pharmacist or an inspector can confirm what the product is and who holds the authorisation for it. The number is the pivot: without it, a Canadian eye drop is not lawfully marketable as a drug.
In the United States the OTC monograph route works differently. A product made inside 21 CFR 349.12 is required to carry the drug facts panel the monograph states, including the active ingredient and its purpose, but it does not carry a product-specific approval number for the same reason a Canadian drug does. It is the monograph number, not a product number, that identifies the basis on which it is sold. That is a structural difference rather than a labelling quality difference, and it is the reason a US list and a Canadian list of the same category never line up column for column.
For the clinic, the practical test is simple. A Canadian product can be checked against a number. A US product can be checked against a monograph. Checking a US sheet for a Canadian-style number and concluding the product is unregistered would be reading the wrong register.
Sources
- 21 CFR 349.12, ophthalmic demulcents
- 21 CFR 349.14, ophthalmic emollients
- 21 CFR 349.10, ophthalmic astringents
- Food and Drug Regulations, C.R.C., c. 870
- Natural Health Products Regulations, SOR/2003-196
- Medical Devices Regulations, SOR/98-282
- Health Canada Drug Product Database
- ISO 15189:2022, medical laboratories
- ISO 13485:2016, medical device quality management
- ISO 14971:2019, risk management of medical devices
- Opto, eye health library
- College of Optometrists of Ontario, standards of practice
- American Academy of Ophthalmology, dry eye
- CCOHS, OSH answers
- Canadian Paediatric Society, documents
- Public Health Ontario, laboratory services test index
- CLSI, clinical and laboratory standards
- Royal College of Dental Surgeons of Ontario
- Canadian Dental Association
- ADA, science and research institute
A drop regimen is only as good as the record that shows it was followed. The printable eye care log is a free sheet with columns for the product, the lot, the date opened and the clinician, so a preserved bottle's in-use period is written down rather than remembered. The eye care record generator at the same log centre sizes the sheet to the number of rooms a clinic runs. No account and no sign-up are needed to open either one.
If the drop you stock sits with equipment, the answer is not generic. Ask a compliance specialist and you will get a written answer specific to your equipment and province, with the regulation or standard it is based on cited.
Related reading
- Eye Drops in Canada vs the US: Which Route Applies?
- Artificial Tears in Canada vs the US: Which Rules Apply?
- Comprehensive Eye Check-Up in Canada vs the US: Which Exam Interval Applies?
CliniEco Medical supplies eye care, laboratory and dental consumables of the kind described in this article. MDEL #35334. This article is written for optometry, laboratory and procurement professionals and is not legal advice; the route to market and the records kept by a clinic belong to the manufacturer and to the requirements that apply to it.
Frequently Asked Questions
Is a preservative-free eye drop a drug or a device in Canada?
It is a drug. An eye drop sold in Canada carries either a Drug Identification Number under the Food and Drug Regulations or a Natural Product Number under the Natural Health Products Regulations. There is no Canadian monograph route that lets an eye drop reach the shelf without a product-specific number.
Can an eye drop be sold in the United States without an approved application?
Yes, where the product stays inside an OTC monograph. Ophthalmic demulcents are covered by 21 CFR 349.12, ophthalmic emollients by 21 CFR 349.14 and ophthalmic astringents by 21 CFR 349.10. A product that remains inside the permitted active and concentration list and makes only the permitted claims can be marketed without a product-specific approval.
Does removing the preservative change the active ingredient?
No. The active ingredient is the same demulcent, emollient or astringent. What changes is the container: a preserved drop is usually a multi-dose bottle that is opened repeatedly, and a preservative-free drop is usually a unit-dose vial that is used once and discarded.
Why is a unit-dose vial more expensive per millilitre?
Because the cost sits in the packaging. Ten 0.4 mL vials deliver the same volume as one 10 mL bottle but use ten containers, each filled and sealed and each discarded after one use. The active ingredient can be identical in both formats.
Does a preserved multi-dose bottle have an in-use period after opening?
Yes. The container is opened many times, so the label carries an in-use window that runs from the moment the bottle is unsealed. A unit-dose vial does not carry that rule, because it is not reused.
How should a clinic store the two formats?
Keep them apart. Put the preserved multi-dose bottles in one position with the in-use window written on the label, and the unit-dose vials in another, so the rule that applies to a bottle is never applied to a vial.
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