Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

In this Discussion

We are working on upgrading our forum software.
Sorry for the temporary design flaws.
The forum works perfectly fine, it just doesn't look pretty.
We will get them fixed shortly.

Allantoin Recrystalization

edited November 2013 in Formulating
I have had several lotions with allantoin recrystalization. I've read conflicting things about how to prevent this - some said it must be heated above a certain temperature to ensure it has all dissolved, some said it is about the rate of cooling (faster or slower is better, I think I've read both). Anyone know how to prevent this reliably? Thank you!

Comments

  • As per the literature available I think it should be added below 50°C, at higher temperatures it will dissolve and recrystallize on cooling. So the trick is I think prolonged mixing (dispersion) to a very fine particle size and which cannot be felt during application. 
    Hope this helps. 
  • You could also try reducing the amount that you use.  Is the allantoin having a noticeable effect in the performance of your product? 
  • @Perry the allowable limit it 0.5-2.0%, even at low concentration it is effective. So if he wants to use it he can lower the limit but the process has to be the same as I previously mentioned.
  • What is it effective at doing?
  • Try it at 0.5% - it should be fine at that level.
  • @Perry it is a skin protectant and anti-irritant, rest of the claims are too complex to just accept them at face value.
  • Allantoin hs been associated with wound healing. The evidence is inferred by the fact that maggots exude it, and maggots are very good at cleaning up septic wounds. It's even a proper recognised medical therapy for bed sores. (How the diet going ?) :D

    I've usually gone to lower concentrations than 0.5%, typically 0.1-0.2% not had any problems with recrystallisation. (I know that the data says that 0.5% is soluble, I've found it difficult to get that all into a hot water phase - YMMV)

    At 0.5% I did see one very old product have crystals in it. Came in as a glass complaint. The product was at least 3 years old, not seen the problem since

     

  • edited November 2013
    @milliachemist - right. I just wonder what level has to be added for a consumer to notice a difference in the performance of the product. When will a consumer definitely see a difference, at 1%, 0.5%, 0.1%, or 0%?

    From a formulators standpoint you should use the lowest level of an ingredient in which you get a consumer perceptible difference.
  • @Perry I absolutely agree with you, it would need some in vivo testing to check it otherwise for a formulator there is no way to know the quantum of effect of different dosages.
  • Perry - good question! I think I notice the effect at 1%, and probably would at less than that. I feel like it softens the skin after a few minutes - similar to the effect from adding AHAs.

    Thanks everyone for the information. I will try keeping it below 50C and .5% or less.

    Duncan, it does feel like small shards of glass. Not quite as sharp, but similar.

    Thank you!
    - If you're not the lead dog, the view never changes -
  • arctat - yes do experiment with it.  For me, at 0.5% it works if I add it at the very end of the heated water phase. 
Sign In or Register to comment.