[juliap3]

I recently had stability testing success with a Vitamin C serum, using sodium Asorbyl Phosphate at 5%, I added anti-oxidants, Gamma Oryzanol and Vitamin E, I think this helped with the oxidation and the serum is packaged in an airless /  container which also helped.  With this success I had hoped the Vit C Toner would have the same success, but this is packaged in a standard bottle with an atomizer so oxygen could possibly get to the product.  I am from the UK so all products have to go through regulatory stability testing and if there are any changes in the 1st 8 weeks of the testing schedule of 12 weeks the formula is deemed unstable, and therefore fails.  I am looking for water based or glycerin based anticoxidant which might improve the stability of the Vit C toner.  .  

[juliap3]

I would like to add zinc oxide to a lip balm but cannot find a reliable source to say how much would be safe. I am using it as a skin protect/ healing properties + and provide some UV protect - what would be a good % - I also have titanium dioxide. Thanks

[juliap3]

Again, many thanks for time on this formula, I have revisted this formula and have removed a few of the ingredients but have kept some too - please don’t shoot me from above.. but wanted to keep some of the actives - the cream has a lovely feel, it appears stable will put it through a freeze / thaw  to double check (I don’t have a lab to do anything too specific) 

Vitamin B3  +  Glucosamine Powder - Bulkactives have reasearch to suggest this is a good combination and have read other studies too. 

Eco silk  (a natural silicone replacement - it does give a very nice feel and in combination with coco-caprylate gives a very smooth silcone feel to the product)

Honeyquat - have removed  /  Hydrolyzed Oat Protein - I am might remove this - supposed to provide film forming properties?? not sure if it does at 1% /  Bearberry & -Licorice Root Extract  have reduced - have read that it can provide “skin brightening & lightening ” properties - more for label appeal I think.

Epidermis & Sebum Balancer - studies have suggested that it is good for sebum balancing (again good label appeal)  /  Hyaluronic Acid  - have removed   /   Allantoin Powder  - have kept  /   Vitamin E - have kept  -  antioxidant at 0.1%

sweet orange  +  lavender +  Rose Geranium + Neroli + Roman Chamomile - fragrance and it smells divine!!

[juliap3]

Thank you for all your comments, I am very “amateur” so your responses have been very helpful, I might have sorted it out by:

removing Sodium Lactate - having read from other posts that it could be the problem

replaced sodium lactate  with panthenol at 1% and increased glycerin to 3% (no tackiness felt)

replaced citric with lactic acid at 1.1% I got the pH down to 6  - I read another post that a formula with zinc should not go below  pH 6 as this could cause the zinc to drift.  I am ok with a pH at 6.

Increased Cetyl Alcohol to 3% to help with the Zinc suspension and have reduced the zinc to 1% and dispersed in the Eco-silk (Isoamyl Laurate, Isoamyl Cocoate) before homgenzing - seems to be ok.

[juliap3]

Thanks Bob for your comments, would you mind if I ask a few questions on issues you raised with my formulation:

you suggest removing “amount of basic material” please could you clarify what you mean as “base” should I lower the %

Re zinc, what would you suggest I use as a suspending agent (I am trying to keep my formula as “natural” as possible

Re active materials - do you mean the Vit B3 and Glucosamine?  what % levels would you suggest?

Re the plant extract, I can add them at the end at your suggestion, but the B3 and glucosamine are added to heated water phase so difficult to add them at the end.  

I appreciate you are busy but would be very grateful of your comments.

Thanks

[juliap3]

Hi Perry

The starting  pH is 7.96, 

I have also used lactic acid but used a high % too, and this altered the viscosity in the same way as using citric acid.

[juliap3]

Hi Bob,

adding Citric at 1.35% affects the viscosity of my cream, it becomes quite stringy 

adding more than 0.5% might cause sun sensitivity, and would I need to label my products accordingly

I can’t find any info to suggest that adding more than 0.5% is ok, so adding 1.35% is ok, all I can find suggests reducing ph using citric acid.