• Formulating

  DHA stability

  Posted by cossci21 on July 26, 2015 at 4:28 am

  Hi Everyone,

  Just wanted to check what pH DHA is most stable at in creams. Also does it react with phenoxyethanol? What are suitable preservatives?

  Thanks

  cossci21 replied 9 years, 4 months ago 3 Members · 3 Replies
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  Microformulation

  Member

  July 26, 2015 at 11:54 am

  DHA is most stable at a pH in the range of 4. Over time the cream will migrate down to about 3.9 pH. It will preserve with phenoxyethanol. It does react with proteins and iron oxides. It works best with nonionic emulsifiers.

  I have had good results with PE9010 as a preservative.

  I have made too many of these products to count. The real secret is treating your DHA as an expendable. Keep it refrigerated until you use it.

• 

  MarkBroussard

  Member

  July 27, 2015 at 1:07 pm

  You might also consider adding some 1,2-Pentylene Glycol to your formulation.

• 

  cossci21

  Member

  July 29, 2015 at 3:06 am

  Thanks for that. I am not sure why i was told not to use phenoxyethanoll then as a preservative.
  cheers

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