• Formulating

  Odd stability color change problem.

  Posted by BobG. on February 8, 2023 at 12:27 pm

  We have a formula with Copper PCA that has a green / blue color. It uses hydroxypropyl starch phosphate and Carbopol Ultrez 20 to add viscosity, stabilize the formula. We see a phenomenon during stability where elevated temp samples lose color from the bottom up. See pics.

  Does anyone have any advice on where to begin troubleshooting / solving the problem?

  

  pharma replied 1 year, 2 months ago 4 Members · 3 Replies

  • formulation
• 3 Replies

• 

  graillotion

  Member

  February 8, 2023 at 4:13 pm

  Can’t see pics.

• 

  ketchito

  Member

  February 9, 2023 at 6:00 am

  Could you try removing Hydroxypropyl starch phosphate? It might be binding to copper from your copper PCA, especially at high T.

• 

  pharma

  Member

  February 12, 2023 at 5:28 am

  What else is in that product?

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