Clarification of timing, on adding HMW Hyaluronic acid to an emulsion.

Graillotion

I would like a little clarification on the correct process for adding hydrated HA to an emulsion.  I have seen several comments to the effect that it should be added post emulsification, to avoid some sort of disruption.

Where it was confusing to me.... was I have not seen a clear explanation of what the disruption is, as well if the form of the HA made a difference?  Is there a difference between adding dry HA....and a pre-hydrated solution of HA, in regards to timing?

So, working with these facts.... I would like for someone to extol on the correct process of adding HMW HA to emulsions (and why...yeah sometimes I'm like having a two year old ).

1) I only add hydrated HA to emulsions.  I create a 1% HMW HA that is preserved and used as needed.

2)  I only use small amounts of this slurry, typically 1-4%.

3) I only use HMW HA.

So, I have made the formulas with adding it to the water phase, and adding it post emulsion.  I have not seen any difference with either method.

I tend to add a lot of ingredients post emulsion, so I always feel like I should add as much as possible up front, to minimize the post emulsion add in percentages.  Maybe this is not important, but somehow my mind wants to minimize the post emulsion add-ins.

My current project will preclude me from using polymerics, so I am going to be increasing the HA in hopes of creating some of that gel undertone, so it is becoming a little more important to me.

Look forward to your feedback.

MarkBroussard

@Graillotion

Best to add it post-emulsification:

(1)  HMW HA can interfere with the formation of the emulsion, particularly with liquid crystal emulsifiers

(2)  Homogenization shreads the HA, so you no longer have HMW HA if you add it pre-emulsification, pre-homogenization

Graillotion

MarkBroussard said:

@Graillotion

Best to add it post-emulsification:

(1)  HMW HA can interfere with the formation of the emulsion, particularly with liquid crystal emulsifiers

(2)  Homogenization shreads the HA, so you no longer have HMW HA if you add it pre-emulsification, pre-homogenization

Thank You Mark....and I do use a pretty good shredder!   

That makes sense, and I also use some LC emulsifiers.

Squinny

This may be of interest (or not!) (PDF) Anomalous Viscosity Behavior in Aqueous Solutions of Hyaluronic Acid (researchgate.net) and I was advised by a highly respected Cosmetic Chemist this when I asked about when to inforpoate HA into my formula
My questions was - All the formula's I have seen with Hyaluronic acid 1% solution I I use your Company's) have it in the heated water phase and I then usually use a purpose hand blender at first stage of mixing when combining my oil and water phases. So is this wrong to do?"
Answer

 "The 1% HA we sell is actually designed to use in the end phase but you can add it into the heating phase.  It is not wrong to do either. "

Cheers Squinny (and sorry if this confuses things but the creams I have made have had no issues by adding HA to the heated Water phase).

Graillotion

MarkBroussard said:

@Graillotion

Best to add it post-emulsification:

(1)  HMW HA can interfere with the formation of the emulsion, particularly with liquid crystal emulsifiers

It is my understanding...that possibly these formations take up to 48 hours to form (could sure be wrong about this).  So, if I am adding this....say 30 minutes post emulsion...am I really gaining anything?

MarkBroussard

@Squinny ; @Graillotion

There is a range of hyaluronic acid molecular weights.  Generally, anything below 200 kDa mw you can add to the water phase pre-emulsification w/o issue.  Any higher mw, you're better off adding post-emulsification.  As I said, homogenization will shread the HA.

Squinny

Thanks Mark I'll do that in future as mine is over 500 kDa.