Slurry Powder - Stability

Hello folks, 

Excuse my wording on the below questions. Powdered products are not my core expertise so some of my wording might be off. 

I have a domed, baked powder product (something like this) with: pigments + fillers/ dimethicone and mineral oil. 

Now I was asked to preform a stability test on this and as expected it's bone dry, shrinking and cracked after a few days in the oven. To me this signifies a product with a short shelf life but how can that be? Do such products have a different stability test protocol? The science seems pretty straightforward or am I missing something here?

Comments

  • BobzchemistBobzchemist Member, PCF student
    edited July 2015
    You're not missing anything - their are no special conditions to evaluate powder stability with. There are powder-specific quality tests, but they're just the same for a fresh product as for an old one.

    What is happening is that the remaining volatile ingredients are evaporating out of your product. There are enough volatiles in it that their absence is leaving behind a shrunken, cracked, dry product.

    This is exactly what "baking" is supposed to prevent - there shouldn't be any volatiles left afterwards. I'd run a water and/or volatile content test to get the exact numbers, but if you don't have an airtight, easily-sealable component, your  customers will see exactly what you're seeing after a few months.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • Much appreciated Bob! The containers are not sealed so I wouldn't be wrong thinking this will happen on the shelves. 
  • BobzchemistBobzchemist Member, PCF student
    Nope, not wrong at all. 

    My understanding of the "baked" powder technology is that they're turning a necessary processing step into a marketing advantage. I don't know where you're getting this product from, but it sounds like they have a near-fatal flaw in either their formula or their manufacturing process, or both.

    I was involved in the development of this type of process many years ago, while I was working for Estee Lauder, and I have a pretty good idea of what's going wrong. The good news is that there are other companies that have already solved this problem, so you know it's do-able. The bad news is that it's probably not a quick fix.


    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
  • This specific product is 'orient' made so there will be very little accountability once money's exchanged. 
    Now my dilemma is how to direct this customer. I don't want to tell them to drop the project but I also don't want to send them to other manufacturers when they only have so much to spend per unit. 
  • BobzchemistBobzchemist Member, PCF student
    Well, one of the possibilities is to have the customer pay more for an air-tight or mostly air-tight compact. Even a clamshell that seals really well used as primary packaging should help some.

    Another possibility is to have the supplier use a less volatile or more of a non-volatile liquid.
    Robert Zonis, Sr. Formulation Chemist, Beaumont Products "All opinions and comments expressed are my own, have no relation to Beaumont Products, are fully copyrighted, and may not be used without written permission."
Sign In or Register to comment.