[em88]

zetein said:

@em88

Using sugar alcohol to dissolve salicylic acid is quite novel. Would you mind sharing your experience?

It’s probably confusing. By sugar alcohol I mean polyalcohols such a glycerin, but also propandiol, butandiol and so on. I believe it’s understandable that blends of alcohols, polyalcohols and PEGs have better dissolving properties compared to each of them alone.
Thanks for pointing it out, and letting me explain it better. 

[em88]

Foldable label?

[em88]

vitalys said:

@em88 I don’t see any incompatibilities with Urea and SA. Formulating emulsions with them could become a pain but nice pleasant emulsions are possible to create, especially with low Urea concentrations ( up to 10-15%).  

pH is the issue. Salicylic acid has keratolytic properties when used as acid. Urea, on the other hand, is not stable at acidic pH.

[em88]

Abdullah said:

@Padmavathi yes but then Paula’s choice has 4% leave on BHA. That makes me confused ????.

By the way, these are for skin. My question is are they safe for hair and scalp? 

I had seen somewhere that salicylic acid makes the hair shaft weaker. But i cant find it now. 

Over 3% of SA is considered a drug. 
Regarding safety, it depends on the pH of your final product.

[em88]

Alcohols, sugar alcohols, PEGs

[em88]

ngarayeva001 said:

My basic question is why such an amazing humectant as urea isn’t very popular? Is it because it’s tricky to formulate with or marketing?

Tricky? More like difficult, especially at higher concentrations and in combination with other acidic active ingredients.:smile: 

[em88]

Nouranm said:

Hello guys, Does anyone has an idea how can I dissolve 10% urea in an ointment for heels with SA and white petroleum, but without water as I want it too heavy for cracks

The approach can be with white petroleum, PEGs, and glycerin. But the ointment will not be very pleasant during applications.

[em88]

vitalys said:

I completely agree with Tobias that Urea is insoluble in any oil/lipid media. 
@Nouranm However, you may make a mixture/paste, which is known in many pharmacopeias and among dermatologists. It includes micronized Urea and fatty base. 
Another approach can be efficient - the Glycerin/Oil (waterless emulsion) or water/oil HIPE  emulsion. It will look as a nice occlusive ointment. You may also find useful including Lactic acid along with some antimicrobial ingredients in this formulation since the chronic cracks are result of untreated infectious inflammation. 
o/w emulsions with the same actives would be less effective. 

I am working on this. The cream is unstable, the same as urea. SA (2%) and urea seem to not be very compatible in creams.

[em88]

Cafe33 said:

em88 said:

Cafe33 said:

PG works as you described but in much smaller percentage. 1.5% was way too high. Somewhere around 0.3-0.4 % works well 

That’s way too low. 
3-5% is the right interval

And you have tried this level of PG? I tried 1.5% and it was terrible. I can’t imagine 5%. 

Yes. I don’t know what was terrible from your side, but for me, it was way better. 

alchemist01 said:

I made a version I quite liked with 4% PG, 1% PEG600, 0.4% Glycerin. It beat Purell in a blind trial with some office workers next door, too!
This was for 70%v/v ethanol, I imagine going lower or higher will give different results.

Glycerin should not do much at that level. I thought about adding PEG too, and I guess it should make the gel have a better sensorial feel. 1% PEG 400 or 600 should be indeed enough. 

[em88]

ketchito said:

@em88 The problem is not having SA with CAPB, the problem is having an anionic surfactant, low pH and CAPB. 

Oh, I somehow missed that while reading your post before. Sorry. That would be correct, but it is something that you have to take into consideration anyway. Adding 2-3% of SA in a shampoo with anionic surfactants may drop the pH about 3-4. At this point, the pH has to be corrected. 

[em88]

What activity exactly? What claims do you have? 

[em88]

ketchito said:

Since they have Salicylic acid and Sodium benzoate, that shampoo might have a fairly low pH. Low pH plus highly anionic surfactants (like SLS and SLES) makes CAPB a no-go, since CAPB behaves as a cationic surfactant at low pH (aprox. below 5), and it might form a precipitate with anionics when added. 

What? I haven’t had issues with my formulations having both SA and CAPB. 

[em88]

Abdullah said:

@Perry @singhc10 thanks.
So what would be the amount of sodium citrate which is is above CAPB, Sodium Xylenesulfonate and SLS? 
And what would it do in such high amount? 

Most likely to dissolve something in an alkaline pH.

[em88]

It will dry up the skin/scalp, but since you are going for an ultra cheap shampoo, I believe this is not something important. 

[em88]

RDchemist15 said:

@em88 Ok so you’re the second person to say that then. I have never read or heard any rationale behind this though. As I said I’ve never noticed a difference between the time it takes SLES to dissolve between salt addition before or not. Have you?

It depends on the quantity of salt. I haven’t tried it. I don’t think the time reduction would be much significant.

[em88]

Might be to facilitate SLES dissolving in water.  

[em88]

First of all “7) TEA to neutralize HEC” is incorrect. HEC does not need to be neutralized! 

“Where am I making a mistake?”
Don’t use HEC, you can try PEG-120 Methyl Glucose Dioleate.

[em88]

Awesome! Good luck with your project. 

[em88]

The apparatus with the funnel is very basic.

You calculate the angle of repose by measuring the height the diameter of the cone base.

The funnel is standard, you can not use any funnel in the lab. 
I guess they are talking about the Hall flow test, which is very similar to the angle of repose test, but it is used for metal powders. 
In the pharmaceutical industry, we use only Housner Ratio, Compressibility index, or Carr Index. 

[em88]

The flowability is not measured in mass/time, nor in %.
The funnel test is to measure the angle of repose, which will give you basically the same thing 

[em88]

5% carbomer is way too much. What type of carbomer are you using?
Regarding your question “Is it safe to alternate sorbitol with glycerine and DEA with TEA?”
Sorbitol is safe, while diethylamine is a straight no! In fact, it is a banned ingredient in cosmetics in the EU countries. 
https://ec.europa.eu/health/scientific_committees/consumer_safety/opinions/sccnfp_opinions_97_04/sccp_out144_en.htm
https://ec.europa.eu/health/scientific_committees/consumer_safety/opinions/sccnfp_opinions_97_04/sccp_out64_en.htm
Triethanolamine is much safer, but if you don’t have access to this ingredient, use NaOH solutions. 
Check the pH of the cream as well.

[em88]

For the Housner Ratio, you will need the Tap Density Tester.

Measure the density of the bulk powder (ρ and then the tapped density (ρT).
After that use the formula HR= ρT/ρB
Use the following table to determine the flowability of the powder blend based on the Housner ratio you calculated.

In the table, you will have the compressibility index as well.

[em88]

There is a small problem with phenolphthalein. It is carcinogenic and it is prohibited in cosmetic products in the EU. 

[em88]

Couldn’t agree more with Belassi.
But if you really must do sterilize the packages (which are better ways to do it especially if they are made of glass), the amount of traces left on the surface will be very low to affect the product. Just make sure to dry the package very well. 

[em88]

Use Methylene blue.