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Author Topic: Why Do Medicines Have A Shorter Shelf-Life In Space ?  (Read 6434 times)

Offline neilep

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Dearest Shelflifeologists,

As a sheepy I of course know everything there is to know about the shelf life of products. It’s all I think about. Yep, thinking about the shelf life and best-before dates of items just dominates my every waking moment.

Look, here are some medicines




Some Medicines For Ewe To Look At



Now, look here....Below is a genuine non-doctored bona-fide photo of the same medicines now on-board a space ship (notice the pilot !  ;))



A Genuine Photo Of Medicines On-Board A Space Craft Earlier Today.


Now I know about the perishability (new word ?) of goods on Terra Firma but in space I’ve been told that the shelf life of medicines is shorter than their counterparts here on Earth !

Why’s that then ?..Why do medicines aboard a space craft (in Space) have a shorter shelf life ?

Ewe see, I don’t know.....and I was told that somebody here might know, so, please change that ‘ might’ into a certainty by telling me why.

Ta

Hugs and shmishes


mwah mwah mwah



Neil
In Space No One Can Here Ewe Prescribe
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx


 

Offline SeanB

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #1 on: 24/07/2011 17:55:41 »
Could be a number of factors. Higher temperatures in storage, along with large temperature storage swings in both the trip there and in storage in the space environment. A more conservative approach to shelf life will result from this high temperature storage, and the space suppliers are traditionally more conservative in this respect. In packaging there traditionally is an autoclave cycle, to kill bacteria, and this will reduce shelf life. All this degrades the active ingredients, and will result in creation of undesirable breakdown products.
 

Offline CZARCAR

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #2 on: 24/07/2011 18:43:32 »
what is shelf life based on? main ingredient,additives, or preservatives? i've eaten some post dated stuff just fine= methinx mfr. wants to sell more
« Last Edit: 24/07/2011 18:45:11 by CZARCAR »
 

Offline neilep

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #3 on: 24/07/2011 19:01:47 »
Could be a number of factors. Higher temperatures in storage, along with large temperature storage swings in both the trip there and in storage in the space environment. A more conservative approach to shelf life will result from this high temperature storage, and the space suppliers are traditionally more conservative in this respect. In packaging there traditionally is an autoclave cycle, to kill bacteria, and this will reduce shelf life. All this degrades the active ingredients, and will result in creation of undesirable breakdown products.


Thanks SeanB Do ewe know why that the fact it's on a space craft means that the storage would be at a high temperature ?
 

Offline neilep

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #4 on: 24/07/2011 19:03:39 »
what is shelf life based on? main ingredient,additives, or preservatives? i've eaten some post dated stuff just fine= methinx mfr. wants to sell more

Thanks CZARCAR...I have no idea what shelf life is based on...What I do know is that it is reduced somewhat by the fact that the items are in space !
 

Offline Geezer

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #5 on: 24/07/2011 19:23:46 »
It could be on account of the continuous X-ray bombardment in space.
 

Offline RD

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #6 on: 24/07/2011 19:47:03 »
There is a greater exposure to cosmic radiation in space, (without the protection of Earth's atmosphere).
Irradiating pharmaceuticals can alter their properties (and consequently efficacy) ...

Quote
an irradiated drug is considered potentially a different drug than the un-irradiated version.
http://www.isomedix.com/TechTeam/Resources/techtip33.html
 

Offline CliffordK

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #7 on: 24/07/2011 21:20:11 »
Personally I don't pay a lot of attention to shelf lives, and will generally go by whether something looks or smells appetizing to eat.

I have never been convinced that "shelf lives" have been based on actual experimental tests.  Even if they are, there are several completely different issues.
  • Loss of efficacy (active ingredient)
  • Buildup of toxic byproducts
  • Contamination
  • Spoilage
A single date doesn't tell you much.

So...  Say you have a 10 yr old Aspirin Pill.
If it has only 90% efficacy over a new pill.  Is that going to make a big difference, assuming it doesn't have toxic byproducts?
Warfarin (Coumadin), however, a 10% change in efficacy could make a big difference, especially if one is mixing batches.
Insulin is a protein, so it would likely degrade somewhat over time, generally with a loss of efficacy.

Toxic byproducts may be a problem with some medications, but presumably not with all medications.  They may also depend on handling.

Contamination and Spoilage can also be controlled with handling, for example a sterile bubble-pack might prevent most contamination or spoilage, especially if packed with an inert gas such as Argon.

Spoilage of injectable meds is far more serious than oral meds.

Anyway, in space, issues might include cosmic rays.  However, there would be some advantages including having a much better controlled environment.  It would be easy enough to build a freezer that would hold temperatures in the realm of liquid Nitrogen, or even colder.  Just hang it out in permanent shade somewhere.  And if one bubble packed the medications, then one could minimize contamination, spoilage, and etc, as well as improving tracking.

I suppose one final issue is a chain of custody issue.  In the USA, if the chain of custody is ever broken, then the meds must be thrown out.  So, for example, if a patient brings in a shopping bag full of meds into a hospital (which the doctors like to see what the patient is actually taking), the bag often gets disposed of because the chain of custody is lost.  On the ISS, I could imagine that once seals get broken, and a number of astronauts pass through, then there is a (remote) possibility of tampering, or mixing up meds.

My guess is that NASA spontaneously has chosen to increase the safety margins without doing the research to back it up.

Another somewhat related question.
3rd world countries are often begging for cheap medicines for critical needs.
However, should they accept out of date meds?
Again, the question should be what is actually wrong with them. 
If it is an analgesic that (potentially) has less analgesic effect, the answer is simply just giving more. 
Again, the decision on whether or not to use the meds should be based on a verified buildup of toxic byproducts, with verified toxic/lethal doses of these byproducts.  Or, perhaps very significant changes in efficacy that would be difficult to compensate for.
 

Offline RD

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #8 on: 24/07/2011 22:42:48 »
It just occurred to me that the atmosphere in a spacecraft can be pure oxygen, (rather than 20% oxygen in air) ... http://en.wikipedia.org/wiki/Apollo-1#Pure_oxygen_atmosphere


[although I believe the International Space Station has an atmosphere very similar to Earth's ] 
« Last Edit: 24/07/2011 22:54:32 by RD »
 

Offline CliffordK

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #9 on: 25/07/2011 00:06:00 »
Interesting notes about the pure oxygen atmosphere.  And, questions about flammability in the Wikipedia article.

At 1 ATM, I think it is best to have a mixed gas atmosphere.  However, I believe there are benefits of running at a lower pressure.  And, with low pressures, one can compensate by increasing the oxygen proportion.  For example, it might be easier to make a ½ ATM spacesuit than a 1 ATM spacesuit.  And there would be benefits of keeping the space suit and cabin pressures the same.

I presume one could the bends from rapid decompression.  Well...  maybe not...
The “bends” rarely occurs with a rapid drop in air pressure below altitudes of 25,000 to 30,000 feet and should not be a problem in airline operations.
Anyway, apparently a partial helium atmosphere has been proposed as one is much less likely to get the bends from helium than Nitrogen, and it is also lighter to carry.
http://astronautics.usc.edu/assets/003/70954.pdf

As long as one doesn't have a large loss, then one wouldn't need to carry large quantities of inert gases.

I wonder what the long-term effects of a low Nitrogen atmosphere would be, say after a few years.  Certainly hospital patients can use oxygen supplements or hydrated oxygen supplements for extended periods of time.

One note about the International Space Center.  They transport breathing oxygen in the form of water, and then discard the excess hydrogen (I think they should capture and recycle the hydrogen, but that's just me).

Did we get off topic?  Sorry  :-\
I think I had suggested above bubble-packing your pills under an inert gas (Helium/Neon/Argon). 
 

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Why Do Medicines Have A Shorter Shelf-Life In Space ?
« Reply #9 on: 25/07/2011 00:06:00 »

 

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