[Paprik]

Short answer - Product is not stable.

Longer answer -
Carbomer - anionic
BTMS - cationic
GMS - non-ionic LOW HLB. 
Hope you see the problem?

What kind of preservative are you using? 

[Paprik]

I would say that 1:20 ratio of SA to PG is good enough. Even 1:10. 

And I would say it is definitely pH dependent - higher pH = salt. pH < 3 = 50% SA bioavailable. 

[Paprik]

YAY! I’m happy for you .. 

Hm, just … how much EDTA have you added? Sorry, it’s just … EDTA is not a pH buffer (or at least I never heard of it in this way). It is a chelating agent. 
TEA would make much more sense to raise pH. 

Anyway, happy it worked, … valuable experience  

[Paprik]

I have already given up trying to get Glycol Distearate to work as a pearliser … I have tried (I believe) everything. And fail every time  

[Paprik]

I’m sorry, did you say you added EDTA to the water to raise the pH? 

[Paprik]

I think I had the same issue with Glycolic Acid and HA serum/peel.
 
You might be right - What is your final pH?
My got too low and HA could not handle it (probably) … once I increased it to around 3 - 3.5 (don’t remember precisely) it got ok. 

Try it. Good luck  

PS. I don’t see any preservative? [Not sure what’s g cham]
Make sure, even you are at very low pH (3), you still include some kind of preservative for any opportunistic organism. 

[Paprik]

That is very sad …  

[Paprik]

Hehe, still confused. You’re saying you’re formulating extra hydrating sunscreen but after that you say “leave my skin matte and not hydrated” ..  

But I guess I know what you mean. 
You need to be careful with what else is in the formula and what type of lipid you’re using. You would need to share your full formula. 
(I’m not familiar with iso-octyl palmitate)

PS. Look at your ZnO dispersion. It is 20%. So if you use it neat on your skin, you could get maximum (if) SPF 20. Now, you won’t be using it neat right? Therefore you cannot even reach SPF 20. 

Formulating sunscreens is not easy. You need to take care about a lot of aspects - stability, homogeneity, coverage on the skin … if you don’t get full coverage it’s almost pointless to use sunscreen as you will still have areas when the sun “hits” the skin. I hope you understand. 

Anyhow, happy formulating!  

[Paprik]

You are really on low side of the input for this preservative. 
Aim for the highest allowed input mate.
You are having basically a perfect environment for microbial growth - water with an amazing food source.

Lower the pH as suggested, add some chelating agent and you could be fine. 

[Paprik]

@Fekher, we simply use PG I guess  
It is compatible. However I do not use PG in surfactants systems as it tends to thin them. It should not be a problem with XG tho (I think). 

You can create mild products using SLES. 
But I get it, there are some milder and more tolerated surfactants/options, especially for baby products.  

[Paprik]

I am sorry if this comes rude to you, but if you don’t know how much Zinc Oxide to add to achieve a specific SPF, I don’t think you are ready to formulate sunscreens. 

But to answer your questions 1 and 2 - 
UV absorbance E max λ @ 1%/1cm is 280 - 370nm @ 1:0.75-1.
Therefore in extremely good base, 1SPF would be approximately 1% w/w. 
Then you can calculate how much of your ZnO dispersion you would required to achieve desired SPF. (And hopefully you already see the problem)

I don’t think I really understand your third question, but if I do, I don’t have answer for you. You would probably need to test it as we don’t know anything about your formula. 

Good luck!  

[Paprik]

drjayseesunish said:

Paprik said:

Any reason why you’re not including anionic surfactant? 
Could you share %?  

We don’t know if this “list of ingredients” would need a conditioning agent.
If it would, you won’t go wrong with, let’s say, Polyquaternium-7, Possibly Guar Hydroxypropyltrimonium chloride and maybe some superfatting agent (Ethoxylated lipid).

@Paprik but once you mentioned anionic and cationic react together to form insoluble content so is it appropriate to use anionic and cationic together in any formulation. 

Hi, but his formula does not contain any cationic surfactant (or at least strong enough to cause any troubles).
Or maybe I don’t understand your comment? What do you think does not add up?

@Abdullah  I believe MPG would be Mono Propylene Glycol.

[Paprik]

Any reason why you’re not including anionic surfactant? 
Could you share %?  

We don’t know if this “list of ingredients” would need a conditioning agent.
If it would, you won’t go wrong with, let’s say, Polyquaternium-7, Possibly Guar Hydroxypropyltrimonium chloride and maybe some superfatting agent (Ethoxylated lipid).

[Paprik]

Xanthan Gum gels the water. 
Imagine it as a fishing net. And micelles (oil trapped in the emulsifiers) as fishes. They will try to swim to each other over time. That is when the fishing net comes and prevents the micelles/fish from moving. = Increased stability. 

Another way to imagine it is something like a facial scrub. Or any product with beads in it. If you put the beads into a water they will either flow on the top or go to the bottom. But if you add gum/polymer (stabiliser) and mix it, it should hold all the beads in place and prevent them from moving. 

Hope this explains it a bit? 

[Paprik]

EDTA is anionic, therefore it does not belong into cationic system. 
[Although I saw many products including it. But from chemical point of view there is not reason]. 
And as Abdullah mentioned, you should be using distilled water. 

If the product gets too viscous after some time, you might have some water/packaging issues. Something like evaporation perhaps.
Have you measured and tested specific gravity during stability testing?

Look also at your formula. No point of using so many cationic surfactants. All do basically the same thing. Stick to one and if you want to have more of them for marketing reasons, add them at 0.1% or less. 

I would think about adding some gum for stability - Guar Hydroxypropropyltrimonium Chloride. 

Try to simplify your formula - go with one lipid, one cationic surfactant and see how it goes. It it will work, you can slowly add ingredients. 

[Paprik]

I actually bought Marine Collagen too and it does have fishy odour. 
Even the website says that :

Please note: this product is derived from fish scales and naturally has a slight, musky-fishy odour. Use of a fragrance may be required depending upon the amount used in the finished product.

So if it is similar product, it might be ok. Just check expiration date?

[Paprik]

@drjayseesunish, hehe, you’re too kind  

I am faaar from being expert in anything. But so far I’ve been focusing on O/W emulsions and currently looking into foaming products. 

You can ask anything, I am pretty sure other members will happily help  

[Paprik]

Final product pH is important. It must be within the range that supports actives, preservative, etc … 

Usually you do not need to adjust pH of your water phase. 

Even if you do and you add some kind of actives at the end (or preservatives for that matter, such as Geogard ECT) it will shift your pH. 

So finish your product [completely] and adjust final pH.

The preservative usually does not get destroyed by “wrong” pH. It only won’t be effective.

[Paprik]

If I say surfactant and emulsifier they both are, chemically speaking, surfactants. 
So surfactant can be the one that foams (cleans) and also the one that is being used in emulsions (emulsifier). Sorry if I confused you before. 

I am not an expert on pomades, but yes, I believe you would use some kind of surfactant (emulsifier) to build viscosity.
Or if you’re making W/O emulsion, you would use low HLB emulsifier. 

[Paprik]

You would need to supply more information. 
Please supply your formula and method if possible … 

[Paprik]

moomin said:

Thanks for all your ‘supporting’ advice! NOT! 
Here is where I am at, I wanted to find a natural deodorant, I found a recipe that included milk of magnesia and essential oils, it worked wonderfully for me (no burns! fancy that!) and so I thought I might make something similar as a sellable product, not using milk of mag but using the stuff in it. I’m not a chemist, don’t have a clue about chemicals, hence why I’m on here, but I just didn’t realise that I would be meeting with a group of guffawing henrys, who think it’s hilarious and ridiculous that someone doesn’t understand about chemistry! well sorry I got it wrong, I misunderstood this site for support and help!

I am sorry if you feel this way.
However, you must realise we are not a bunch of mommy bloggers. We deal with real life scenarios and issues. We do use real science here. And if we see a problem, we deal with that in that way.

We do help for free, only for our good feelings and some people abuse it. 
Try to take the advise from a different angle and approach your problem with all the help you got. Or describe your problem in different way. 

Happy and safe formulating. 

[Paprik]

What exactly do you need to determine?
I am not sure what you want to calculate. 

Share your formula, share your problem or what would you like to improve and after that we can help. 

[Paprik]

I do not have any source for this, [hopefully someone has], but the main thing you would worry about is actives. The active or the product type would tell you what pH do you need. 
Let’s say you are formulating with ascorbic acid .. the best pH for its stability (even it will still be around 2 months) would be 3 - 3.5. 
Conditioners need lower pH for its strong charge - 4 - 4.5. 
Other active might need pH 6-7, therefore you would formulate for this pH (I believe MAP would need this) etc …. 

So investigate every ingredients, how to incorporate it into your formula and stick to it. 

[Paprik]

You need to realise that surfactant has much more stronger charge in compare to cationic gum/polymer. 
If you would mix cationic (BTMS, Cetrimonium Chloride … ) and anionic (Sodium Coco Sulfate, Sodium Cocoyl Methyl Isethionate…) they would act as magnets - cling together and would form insoluble substances. 

I said that BTMS is suitable for hair masks .. also for pomades. Along with non-ionic emulsifiers.

You usually use anionic for its cleansing ability (foaming surfactants) or emulsifying properties (emulsifiers) … 

Hope this makes more sense now?

[Paprik]

drjayseesunish said:

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@Paprik thank you!

@Paprik , Is it suitable for formulation of hair mask, a leave on product? Or we can use only in hair shampoo?

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It is very suitable in hair mask and also in leave on products. However check regulations, you usually use only little amount in leave on products. 

Shampoos are usually anionic (negatively charged) so it is not suitable to use it in shampoo at all. [You can use cationically charged gum or polymer tho .. such as Polyquaternium-7 and Guar Hydroxypropyltrimonium Chloride].

Happy formulating.