Is it normal for OTC eyedrops to be yellow?

March 18, 2013 9:06 AM

I just purchased some eye drops (Superdrug Irritated Eye Drops) and before putting any in my eyes noticed that the liquid is tinted a very faint yellowish color. Is this normal?

I've compared them to some "Superdrug Brightening Eye Drops" and the brightening ones have no colored tint. No eye drops or contact solution I've used before has been any color at all, that I've noticed. The only reason I even know what color these are is because I had trouble getting the cap off and spilled some.

I know the safe answer is "don't use them" but if someone can confirm that they SHOULD be this color then I would.

I've tasted them and they taste like eye drops. Ingredients are calendula extract, hamamelis extract, disodium edetate, sodium chloride, hydroxymethlglycinate, borate buffer, water. Could any of these tinge the eye drops yellow?

posted by Polychrome to Health & Fitness (6 answers total)

Best answer: I've never used them, but if calendula extract is the main ingredient, it certainly could. Marigolds are yellow.
posted by thetortoise at 9:17 AM on March 18, 2013

Did you try contacting the manufacturer?
posted by Julnyes at 9:18 AM on March 18, 2013

Response by poster: I have contacted the manufacturer and will update if I ever hear from them. I'm at my desk with dry eyes now though so asked here in hopes of a quicker response. The expiration date is 09/2015, by the way.
posted by Polychrome at 9:24 AM on March 18, 2013

I'm no chemist, but I've used more eye drops over the past 25 years than you can poke a stick at. And yes, some of them were yellow-tinted (or bright yellow, in one case, but they were for conjunctivitis). As long as the seal was intact and expiration date good, I'd totally use them.

Or, call your local pharmacy (drugstore?) and ask to speak to the pharmacist. They should know, or find out if they don't.
posted by Salamander at 9:32 AM on March 18, 2013

Ask your pharmacist.
posted by gaspode at 10:01 AM on March 18, 2013

Best answer: I was thinking phenolphthalein which is in some eyedrops, which famously (allegedly) changes the colour of one's urine if one has consumed enough of it (it is an "pH indicator" that changes colour depending on the acidity/alkalinity it's in) while appearing innoculous in beer. But that's not the case.

Disodium edetate is EDTA, a common chelator of calcium ions. It's there as a preservative. It's in everything. Not going to contribute to yellowness. Mostly harmless.

Sodium chloride is table salt. Think saline solution. It's there so it doesn't make the cells in your eyes burst (see tonicity).

Hydroxymethlglycinate is a rather common preservative that slowly degrades to release formaldehyde which crosslinks proteins and as such is considered to have antimicrobial properties.

Borate buffer is there to keep the pH (acidity/alkalinity) stable so it doesn't burn or melt your eyeballs.

Hamamelis is witchhazel. Why would you want an astringent in your eyeballs? Oh right, maybe for closing capillaries to resolve "bloodshot" eyes?

Calendula (I had to look this up) is marigold. That's possibly where the yellow comes from.

Personally, I'd never use an eyedrop that includes "extract" in it's ingredients list (does your country mandate a "medicinal ingredients" list as well as a "ingredients list"?). Extract by its very nature = manufacturer has no idea exactly what they're putting into their product or use "extract" specifically to avoid saying what's in their product (ie,. hydrolyzed yeast extract - check your Doritos - contains a lot of glutamatic acid salts; MSG).
posted by porpoise at 8:10 PM on March 18, 2013