Home Cosmetic Science Talk Formulating preservative mapping issues

  • preservative mapping issues

    Posted by tattvas on September 5, 2018 at 3:52 am

     hello…i need your guidance regard to preservatives.. most of our customer got negative opinion about parabens so we avoid it totally but so phenoxy also not on good radar… i understand preservative is totally PH related. now when we talk to suppliers and try to understand preservative its vast area. can any one suggest a preservatives or set of preservative to use in leave on products, rinse of products 

    microformulation replied 5 years, 5 months ago 5 Members · 32 Replies
  • 32 Replies
  • ngarayeva001

    Member
    September 5, 2018 at 9:12 am

    This really depends on the type of a product. You are correct, it is pH dependent, however, a scrub in a jar packaging (rinse off) that is stored in a humid warm place (bathroom) and that is scooped out of this jar with wet fingers would need a very strong preservative system. Much stronger than, say a spray in airtight container (leave on). So you should think about it from the product perspective not leave on/rinse off. You can try Sodium benzoate & Potassium sorbate blend (it’s kinda broad spectrum and kinda intended for both rinse off and leave on products) but I don’t think it will be as effective as parabens.

  • ngarayeva001

    Member
    September 5, 2018 at 9:20 am

    Also, Dehydroacetic acid & Benzyl alcohol blend is a non paraben, non-formaldehyde, non-isothiazolone based preservative system. It is acceptable in organic formulations. I can’t say anything about efficacy.

  • tattvas

    Member
    September 6, 2018 at 3:03 am

    @ngarayeva001…will sodium benzoate and potassium sorbate work in shampoos?…as the ph will be around 6, wont it will be ineffective after a period on shelf life.. and can what percentage of dehydroacetic acid and benzyl alcohol do you recommend.?  presently we are formulating baby wash n shampoo, moisturizer and adult shampoos with plant based surfactant(only i adult shampoo)…. one more thing i really wanted to mention here.. it is such a relief to found something like this forum where i can gain from other experiences.. thank you all 

  • markbroussard

    Member
    September 6, 2018 at 3:17 am

    Here are a couple of options you can try that are effective at higher pH levels:

    (1)   Lonicera Caprifolium (Honeysuckle) flower extract, Lonicera Japonica (Honeysuckle) flower extract, water

    (2)   Phenethyl Alcohol, Propanediol, Pentylene Glycol (Lincoln Fine Ingredients)

  • ngarayeva001

    Member
    September 6, 2018 at 8:23 am

    @Tattvas this is what manufacturer says: “Sodium benzoate & Potassium sorbate is normally used in concentrations of 0.5 – 1.5 %. It does not effect the foaming results of shampoo and shower gel making it highly useful as a preservation system in these products, providing the pH is less than 5.5. Sodium benzoate & Potassium sorbate is fully effective in both cationic and non-ionic systems”. So you actuclly can reduce pH to 5 in no other preservative works for you. I understand it’s all about perception of the customers, but nothing is better than parabens…

  • tattvas

    Member
    September 6, 2018 at 8:58 am

     yea @ngarayeva001..its all marketing gimmick.. will try sodium benzoate and potassium in baby wash and adult shampoo 

  • tattvas

    Member
    September 6, 2018 at 9:30 am

    @MarkBroussard…yeah will try these in liquid soap

  • tattvas

    Member
    September 6, 2018 at 9:41 am

    @ngarayeva001… i need ur opinion abt baby moisturiser.

    presently we are formulating this, so far no issues on front of texture, feel and preserving it as we make it small batches. but we are thinking of making it for longer shelf life.

    water phase:

    infused dandelion, neem, licorice,

    aloe vera aqua ( 10% of total water
    glycerin - 10 %
    xanthum gum -0.5 %

    Oil Phase:
    jojoba, shea, vit e, safflower, almond, avocado,beeswax(0.5%)
    sebuckthorn oil=total 11 %

    emollient
    cetyl alcohol- 3-5%
    glycerol oleate- 1%

    preservative - sodium benzoate-1 %
    ethylhexylglycerin- 0.5%

  • sven

    Member
    September 6, 2018 at 10:59 am

    @nagarayeva001 in your opinion is the 5.5ph the absolute top end? My shampoo ends up between 5-6 ph

  • ngarayeva001

    Member
    September 6, 2018 at 11:27 am

    @Tattvas, to comment on this I need to know exact % of each individual oil. The reason for this is that, if you want to create a stable emulsion, you have to calculate HLB of our oil phase to make sure you are using the right emlsifyer. It is very important. What I see at the moment is that you are using oils with different HLBs ranging from 6 to 15.5 (btw cetyl is part of your oil phase too) and an emulsifier for water in oil emulsions at a rather low %. You probably need two emulsifiers with different HLBs to make sure that the formula is stable. Also, not related to the stability, as per my experience glycerine at % more than 4 tends to make the formula very tacky.

  • ngarayeva001

    Member
    September 6, 2018 at 11:33 am

    @sven I didn’t say 5.5 is the top end. But Tattvas is looking for a natural preservative system (which are not broad pH like parabens and phenoxyethanol). The one I mentioned requires pH of not higher than 5.5 and I am saying that in the worst case scenario if no other preservative system works the formula can be adjusted for this preservative.

  • tattvas

    Member
    September 6, 2018 at 1:08 pm

    @ngarayeva001

    jojoba- 1% =                       hlb = 6.5/11=> 0.41
    shea butter- 2%, =              hlb = 2×8/11=>1
    Vitamin E- 1%, =                 hlb= 0.41
    safflower oil - 3 %=             hlb= 8×3/11=>1.5
    Almond oil - 3%,=               hlb= 3×7/11=>1.31
    Avocado oil- 2%,                  hlb =7×2/11=>0.87
    Beeswax- 0.5%=                  hlb => 0.5×12/11=.19
    seabuckthorn oil - 0.5 %=    hlb = >.13

    cetyl alcohol 4 % =  HLB required=>3.87

    total hlb = 9.69

    glycerin we were using 3 % earlier but we found it not upto the mark. trying another supplier for that

  • tattvas

    Member
    September 6, 2018 at 1:13 pm

    @ngarayeva001… i divided individual oil percentage with total and then multiply with individual hlb.. total oil percentage including cetyl is 16 not 11… though calculation is right.. so it will come across near 10

  • ngarayeva001

    Member
    September 6, 2018 at 1:46 pm

    @Tattvas, I recalculated, and my number is also close to 10. So, Glyceryl Oleate alone is not the best option for this formula, because it has required HLB of 3.5. You can try  a blend of high and low HLB emulsifiers. Calculation is the same as for the oil phase. For example if you take PEG-100 (HLB 18.8) at 1.5% and Glyceryl Stearate (HLB 3.8) at 2% you will arrive to total HLB of around 10. I used this example because I prefer this particular blend, but if you don’t want to use PEGs because of marketing, you can try combining Glyceryl Oleate with some high HLB emulsifier that will be in line with your marketing claims. Maybe Polysorbates?

  • ngarayeva001

    Member
    September 6, 2018 at 1:55 pm

    One general comment on oils. You have a nice blend of saturated and unsaturated fats here, but I have an observation from reading ingredients of countless number of baby products. You will not see a lot of oils there. I remember I saw shea butter in one product, but they mostly use petrolatum and other syntetic oils. The reason is that syntetic oils don’t cause allergies yet do the job (emollient). It also could be due to the fact that synthetic oils are cheap and people don’t tend to pay much for baby lotions. Nevertheless, I would probably think twice about nut oils (Almond) in baby products.

  • microformulation

    Member
    September 6, 2018 at 2:16 pm

  • microformulation

    Member
    September 6, 2018 at 2:21 pm
    Your Tocopherol is far too high if you are at 1% net Tocopherol.
    Beeswax is NOT an emulsifier and as you can see actually has a required HLB of 12 (Calculations are based on http://pharmacy.creighton.edu/pha313/book/R-Chapter09.pdf)
    Your required HLB is 9.16
    My calculations are exact, but in the big picture, it is misleading. The HLB system is a guide to help design the emulsification system and does not always act as predictably as the math. It is a starting point.
  • ngarayeva001

    Member
    September 6, 2018 at 2:48 pm

    Thank you for the guide @Microformulation, I guess my oils HLB list is less precise than yours as my HLB is 9.54. I agree it’s a starting point and it doesn’t always work as expected, that’s why I suggested Glyceryl Stearate and PEG-100 mix. It works pretty well in this type of emulsions. Also, there is Cetyl Alcohol which is advised as a thickener for this blend in this formula. 

  • microformulation

    Member
    September 6, 2018 at 3:11 pm
    @ngarayeva001 Actually, the values that we both arrived at are so close that they would be treated as identical for all intents and purposes when designing the emulsification system. Again, it is a fallacy to believe that the system is that precise.
    Also, we need to keep in mind that the HLB system works primarily with non-ionic surfactants. Many of these emulsifiers will not be allowable under any defined “natural standard” as they are ethoxylated. As you perform more Formulations under a natural standard, you will see HLB become increasingly irrelevant. You will more often see a ratio of emulsifier to oil used in these cases. In any case, the distributors provide great guidance.
    In the end, your best emulsification system will always be determined during the lab work. HLB gives a utopia result. Lab work gives us the actual best result.
    As for a preservative, I agree with @MarkBroussard about the Lincoln Fine Ingredients preservatives being an option. Keep in mind that regardless of how you go, you will want to use a hurdle technique to optimize your preservative system. You will want to do challenge testing of the final Formula. Lastly, any reputable manufacturer will be testing as part of a QA/QC Program.
  • microformulation

    Member
    September 6, 2018 at 3:14 pm
    This is another option. It is an ECOCERT/COSMOS product.
    Now, no offense to anyone, please, but keep in mind that many of these newer “natural” preservatives are VERY sensitive to sanitary conditions during manufacturing. These conditions are difficult to achieve for some lines in their facilities.
  • ngarayeva001

    Member
    September 6, 2018 at 3:15 pm

    @Microformulation can you suggest a high HLB emulsifier that might work with Glyceryl Oleate? I said potentially polysorbates, because I know that Sorbitan Oleate which is also low HLB mixes well with polysorbates.

  • ngarayeva001

    Member
    September 6, 2018 at 3:22 pm

    @Microformulation, I only have experience with non-ionic emulsifiers so far. I don’t know whether it’s even scientific, but if I am not sure if the formula stable I am just adding a polymer emulsifier. They tend fix all imperfections. I understand that it’s not an option with natural formulations though.

  • microformulation

    Member
    September 6, 2018 at 3:42 pm
    This is the designed Emulsification system. It calculates the total emulsifier as 5% but this I will often tweak. Please don’t be impressed by all the decimal points, as the math presumes a level of accuracy not seen in real life.
    I have the quoted HLB of Glyceryl Oleate as “3-4” per the Dermofeel PO datasheet.
    One error that was made was to break-up the PEG-100 Stearate and the Glyceryl Stearate up and use their individual HLB’s. This combination is an extremely common raw material (Arlacel 165, Simusol 165, Tego 165) and the material combination has an assigned HLB of 11.
    So, in my case, you would have 5% total emulsifiers, comprised of 1.23% Glyceryl Oleate and 3.77% Arlacel 165.
    Lastly, any emulsification system should be stabilized. In this case, I would add either Carbomer or a natural gum (like Solagum AX) in the external (Aqueous) phase.
    My only concern is that if you infer a general direction of the original posted Formula, it looks like they are positioning themselves for a “natural” market. Most would have a problem with the Peg-100 Stearate and any carbomer.
  • tattvas

    Member
    September 6, 2018 at 5:00 pm

    @ngarayeva001, @Microformulation… i have PEG 100 in stock…but  what about cocamide MEA in moisturizer?

  • microformulation

    Member
    September 6, 2018 at 5:18 pm

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