Does this cationic emulsion need another anti fungal preservative?

Tagged: formalin, lotion, preservative

Formulating

Does this cationic emulsion need another anti fungal preservative?

Posted by Abdullah on October 31, 2022 at 1:09 pm

This is a lotion formula for dry skin.
10 People who have used it like it very much and couldn’t tell any difference in mildness or irritation on skin with same formula preserved with 0.5% phenoxyethanol+ 0.15% caprylhydroxamic acid instead of formalin. Changing preservative system to 0.1% formalin is a big cost saving for me.
My question is about preservation spectrum of formalin at this pH.

Do i need an anti fungal preservative with 0.1% formalin in this cationic emulsion at pH 4.5 or not?

Formula
Glycerin 12%
Petrolatum 4%
Behentrimonium chloride 0.5% active
GMS 2%
Cetearyl alcohol 1%
Lactic acid 0.4% active
Fragrance 0.05%
Formalin 0.1%(370ppm formaldehyde)
Water
pH 4.5

Abdullah replied 2 years, 1 month ago 3 Members · 15 Replies
15 Replies

ketchito

Member
November 1, 2022 at 12:03 am

Abdullah said:

This is a lotion formula for dry skin.
10 People who have used it like it very much and couldn’t tell any difference in mildness or irritation on skin with same formula preserved with 0.5% phenoxyethanol+ 0.15% caprylhydroxamic acid instead of formalin. Changing preservative system to 0.1% formalin is a big cost saving for me.
My question is about preservation spectrum of formalin at this pH.

Do i need an anti fungal preservative with 0.1% formalin in this cationic emulsion at pH 4.5 or not?

Formula
Glycerin 12%
Petrolatum 4%
Behentrimonium chloride 0.5% active
GMS 2%
Cetearyl alcohol 1%
Lactic acid 0.4% active
Fragrance 0.05%
Formalin 0.1%(370ppm formaldehyde)
Water
pH 4.5

@Abdullah At that pH and having an organic acid, you might be OK, but maybe someone with more experience could give more perspective.

Just out of curiosity, did you chek the stability of your formula under accelerated stability conditions?
PhilGeis

Member
November 1, 2022 at 9:25 am

What is packaging?
Abdullah

Member
November 1, 2022 at 10:06 am

ketchito said:

Abdullah said:

This is a lotion formula for dry skin.
10 People who have used it like it very much and couldn’t tell any difference in mildness or irritation on skin with same formula preserved with 0.5% phenoxyethanol+ 0.15% caprylhydroxamic acid instead of formalin. Changing preservative system to 0.1% formalin is a big cost saving for me.
My question is about preservation spectrum of formalin at this pH.

Do i need an anti fungal preservative with 0.1% formalin in this cationic emulsion at pH 4.5 or not?

Formula
Glycerin 12%
Petrolatum 4%
Behentrimonium chloride 0.5% active
GMS 2%
Cetearyl alcohol 1%
Lactic acid 0.4% active
Fragrance 0.05%
Formalin 0.1%(370ppm formaldehyde)
Water
pH 4.5

@Abdullah At that pH and having an organic acid, you might be OK, but maybe someone with more experience could give more perspective.

Just out of curiosity, did you chek the stability of your formula under accelerated stability conditions?

Does 0.4% lactic acid have any microbial effect?

Yes it is very stable.
Abdullah

Member
November 1, 2022 at 10:11 am

PhilGeis said:

What is packaging?

It is 120ml bottle with flip top cap and 220ml bottle with Disc top cap.
PhilGeis

Member
November 1, 2022 at 11:03 am

You prob do need an antifungal preservative.
The question of formaldehyde is stability. That’s why the releasers.
Abdullah

Member
November 1, 2022 at 11:33 am

PhilGeis said:

You prob do need an antifungal preservative.
The question of formaldehyde is stability. That’s why the releasers.

Got it

What if i reduce the pH to 4 with lactic acid?
Do i still need an anti fungal?

What about 0.2%(0.11% active) DMDM hydantoin at pH 4.5 or 4 as only preservative instead of formalin?
PhilGeis

Member
November 1, 2022 at 11:38 am

Neither helps but prefer the DMDM H for stability.
Abdullah

Member
November 1, 2022 at 11:56 am

PhilGeis said:

Neither helps but prefer the DMDM H for stability.

Thanks

For caps, which one is better for preservation of product?
Flip top cap or disk top cap?
PhilGeis

Member
November 1, 2022 at 12:27 pm

Disk cap - can you describe?
Abdullah

Member
November 1, 2022 at 1:01 pm

PhilGeis said:

Disk cap - can you describe?

This one
PhilGeis

Member
November 1, 2022 at 1:42 pm

Thanks Prob no diff - maybe little more is it places finger on orifice to close but flip top allows water and gravity-accessed particles when open.
https://journals.asm.org/doi/abs/10.1128/aem.56.5.1476-1479.1990
Abdullah

Member
November 1, 2022 at 2:00 pm

PhilGeis said:

Thanks Prob no diff - maybe little more is it places finger on orifice to close but flip top allows water and gravity-accessed particles when open.
https://journals.asm.org/doi/abs/10.1128/aem.56.5.1476-1479.1990

Thanks a lot
Abdullah

Member
November 1, 2022 at 2:42 pm

@PhilGeis if i use pump instead of flip top cap for this lotion, will 0.1% formalin or 0.2% DMDM hydantoin be able to protect it from fungi?
PhilGeis

Member
November 2, 2022 at 10:19 am

Prob not. Fungi are ubiquitous.
Abdullah

Member
November 2, 2022 at 12:00 pm

PhilGeis said:

Prob not. Fungi are ubiquitous.

Got it
Thanks