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Creams stability tests
Hello,
I was wondering how do you do the stability tests for creams.I put the cream in some sample tubes. Tubes must be sealed except 1-2 tubes which are unsealed. I check their stability in normal and accelerated conditions after 1 month.
How would you interpret if the cream was stable (even the pH was stable) in accelerated conditions after a month, but not stable (fazes were separated) after two months, for opened tubes? -
10 Replies
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you’re not manufacturing or storing the product in unsealed, i.e. open tubes - what do you hope to achieve by carrying out stability tests under those conditions?
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The main reason was to have an idea about the stability of the cream after the tube was opened. Normally the shelf life of an unsealed cream is less than one sealed.
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An unsealed cream is not an ideal nor particularly normal incident. More of an anomaly. We test our samples in a closed flint glass jar which we purchase from SKS. When available, the actual packaging would be even more ideal, but with the rapid R&D cycles we have, the packaging is usually lagging behind stability testing.
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Answer is simple an open package for that period of time is an anomaly in the real world but you can always put directions on label to seal container tightly after each use if you have concerns.
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By unseal tube, I mean it has the cap closed, but the tube itself is unsealed. So the test is made to have an idea of how stable the product is after the first use.
From what I have seen, the stability test in accelerated condition is not very reliable for semisolids. Keeping the cream in high temperature and high humidity for a long period of time (2-6 months) will almost always result in degradation/faze separation etc. -
I presume you mean after tamper evident seal is broken (6-8 mo at high ?temp) and with that being the case do you run a control/s?
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Yes.
Many products have specified the shelf life (for ex. 2 years) and shelf life after the first use (for ex. 6 months)
That is what I’m trying to determine. -
got it.I had an experience once when a client(15 years ago) opened an unsealed (I think) tube of a cream for demonstration and out came about 5-10 cc of water before cream.Maybe think of publishing your work when you are finished.
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Exactly. I want to avoid this issue. Anyway till avoiding it I have to deal with the data regarding accelerated condition, which are failed for 2 months of stability….
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Stability test need to perform by laboratory. The product is stored at the 5 and 40 gr. celsius in termostate. After that we check ph and other parameters.
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