Ebay and Coaguchek PT Strips

[Protimenow]

When they're exposed to air for too long (I think it's ten minutes), the strips are unusable.

OTOH - Coag-Sense strips aren't sensitive to exposure - According to a former president, who I had regular contact with, even if you open the sealed packet that they came in, they were still good for days - if not longer - as long as you didn't test with them. Their current meters and strips are date coded, so you can't use expired strips (unless, of course, you change the date on the meter).

 

[pellicle]

When they're exposed to air for too long (I think it's ten minutes), the strips are unusable.

I'd like some shred of supporting evidence on this claim

1. the bottle is not an environment that excludes air
2. every time you open the bottle air will mix

I understand that the lid of the bottle has a desiccant in the lid, and so its possible that if you remove the strips from the bottle and leave them out on the bench in the middle of high humidity summers that they may spoil.

I store mine in the bottle, not scattered about on the kitchen bench, so I think this claim is a bit exaggerated.

Yes they have a use by date, but if you follow the directions then they will (and always have for me in the last 12 years of using these) lasted exactly as expected and have consistently given me good readings.

I would request that if you have a suspicion or are making a conjecture say so, but to make a statement like you have without supporting evidence is pretty irresponsible.

PS: I just did this search and found this document (download from here or read the file attached)

Summary:

In summary, we found that test strip results of CoaguChek XS were not significantly affected after repeated exposure to air under Korean summer conditions and we conclude that if patients close the vial caps, the test strips can be safely used for the POC monitoring of INR.​

... use it, live by it

 

[tom in MO]

What kind of problem did they notify you of? Did they replace the problematic strips?

I do not remember what the problem was. There was a list of lot numbers that I was sent. Awhile later, my supplier sent me replacement strips.

I have received shipment where something was dropped on the box, crushing the plastic vial that contained the strips exposing them to the air. I contacted my supplier, who passed it on to Roche, who called me and replaced the plastic vial. I was told not to use the ones in the broken vial.

 

[Protimenow]

I was stating what I recall was included with the strips. Unless Roche has changed their documentation, they advise to use the strips within ten minutes of removing them from the tube. Keeping them in the tube does expose them to air - but the exposure is much less than the exposure to a strip that is no longer in the tube.

True, I haven't revisited the documents I quoted, but I was comfortable in making the statement.
I'll recheck and update my statement if it's incorrect.

On Page 20 of the CoaguChek XS user manual it says 'You have 10 minutes to use a test strip once you remove it from the container.' I was just quoting what Roche says. Whether or not a strip fails or is unusable after ten minutes is something that I've never tried to verify.

Further, the paper that you linked to your reply was related to strips that were in tubes opened for one minute at a time - not strips that were removed from the tube and left with full exposure to air. The dessicant in the tube may have been capable of removing the humid air that entered the tube during the one minute periods that the tube was uncapped.

Had the researchers actually removed the strips and left them exposed to air and the humid Korean summer, they may have had different results. The XS manual cautions against touching the strips with moist or wet hands.

Presumably, the strips are affected by moisture in the air - it may be possible that the length of time a strip is out of the tube and still usable probably depends on the humidity of the room where the strips are left out of the tube - in less humid environments, the '10 minute' limit might be extended.


What I stated wasn't conjecture or suspicion - it was something that I remembered from the manual, and that was confirmed when I revisited the manual.

 

[pellicle]

Good morning

What I stated wasn't conjecture or suspicion - it was something that I remembered from the manual, and that was confirmed when I revisited the manual.

I see .. well lets revisit that

When they're exposed to air for too long (I think it's ten minutes), the strips are unusable.

looks like a conjecture to me, and then you go on to say something based on just a personal experience:

OTOH - Coag-Sense strips aren't sensitive to exposure - According to a former president, who I had regular contact with, even if you open the sealed packet that they came in, they were still good for days - if not longer - as long as you didn't test with them

where you state something about sealed packets which makes the suggestion about storage.

To a casual reader what you seem to say is to imply that "the strips are spoiled by air" which introduces concerns that really aren't there.

I'm willing to bet that Roche has built in enough fail safes that if you behave in a reasonable way and:

1. open the bottle and remove a strip to conduct a test
2. conduct the test in a reasonable manner (not suddenly decide to go out for the day and leave the strip on the kitchen counter)

the strip will be fine.

I'll go further and say that you can then change you mind about the test, return the strip to the bottle and then test with it later with zero problems right up to the use-by date of the strip.

Further I'm willing to bet that I can leave a strip out for hours, and return it and there be no difference.

Tell you what, I'll test that if you like.

If you're going to muse then say its a muse, don't muse about things and instil uncertainty in people who don't know better.

 

[Protimenow]

Roche said you must run a test within ten minutes of removing the strip from the tube.

I haven't felt like wasting a strip to confirm this. For all I know, this could be purely marketing. For all I know, I can remove a strip, strap it to the roof of my car, and drive a few miles, then use it to make an accurate test a week later. I don't know.

The chemicals on the strip MIGHT be very sensitive to moisture - which is why Roche says not to get the strips wet, or handle them with moist hands. I can't say with absolute certainty that what Roche advises is completely accurate.

In regards to the Coag-Sense strips, the issue isn't just storage - they're packed in a sealed foil packet. It's about the ability to keep the strip outside of its foil package for hours - maybe even days - maybe even a week or more (I haven't tested this), and still run an accurate test. Because the reaction is not electrochemical like the XS, and, rather mixes a reagent with the blood and does a physical test for clotting, the strips are apparently not affected by ambient humidity.