Article by: Perry Romanowski

We had an interesting question posed by one of our readers who has a background in Chemical Engineering.  Specifically, he wanted to know if there were some general guidelines for scaling up a formulation and creating a manufacturing procedure.  Since we’ve never written specifically about this in the past, here are eight tips that can make your scale up from the lab to the production plant easier.  While none of these tips will apply to every formula they are a good guideline to help you craft your manufacturing procedures.

1. Start with abundance

When making a batch you should fill the tank up with the ingredient that is the most abundant in the formulation.  Since the vast majority of formulations are water-based, this typically means you fill the tank first with water.

2. Put in your powders

Since many water soluble powders can take a long time to disperse or dissolve, it is best that you get those ingredients mixing.  This will speed things up considerably.  You also don’t have to necessarily wait until every bit of the powder is evenly mixed into the formula before adding more ingredients on top.

3.  Heat helps (usually)

Even if a formulation doesn’t need to be heated to melt the ingredients, it is often helpful to heat up the batch a bit to speed things up.  In general, warmer ingredients take less time to blend.  Note that this is not always the case.  In fact, cellulose raw materials often go into solution faster when the water is cold.

4.  Go 10 degrees C higher

When you are creating an emulsion or working with solids that need to be heated past their melting point, a good guide for manufacturing procedures is to heat the batch 10 degrees C higher than the highest melting point of the ingredients you are using.  For most emulsion this means your batch should be anywhere from 75 – 80C.

5.  Twenty minutes of mixing

While it depends on your mixing tank, a minimum of twenty minutes mixing after blending the oil and water phase together is needed.  If you don’t have good turnover it could take a lot longer.

6. Add fragrances and preservatives last

Since these ingredients can break down when heated, it is best to add them at the very end when all your heating and cooling is completed.  This will minimize ingredient degradation.

7.  Color early

Add colors early on in the batch and check the color versus a color standard. If you make a mistake you can easily pitch the batch without much cost.

8.  Neutralize at the end

Finally, neutralize your formulas that require it (gels & anything with Carbomer) at the end.  This should be the last ingredient you add.  It will help minimize the amount of air you get in the formula.

Of course, these are just general guidelines and every specific cosmetic formulation is going to be different.  Sometimes things that work easily in the lab don’t work so easily in a 2000 gallon tank so it will take some experimentation.

Do you have more suggestions?  Add them in the comments below!

7 comments

  1. JL

    If your oil phase has lot of wax, don’t add anything that will make it opaque until you can verify all the waxes are melted. Often it takes a lot longer than you’d think to melt blocks of beeswax, or to completely melt polyethylene pastilles.

    If you have to grind pigment, get that started first and before there is too much in the tank. Often it’s best to load the tank with a major liquid ingredient like water or mineral oil or dimethicone only, add the pigments, and grind until there are no spots. You really don’t want color spots when you have all your ingredients added.

    Keep your oil phase and water phase close to the same temperature when emulsifying.

    Adjust the pH of your water phase before emulsifying with w/s emulsions.

    Dilute your base if needed when neutralizing gums and gels to avoid local overneutralization when adding.

    Lastly, get to know the equipment on the production floor inside and out, know the capabilities, and know which lab equipment equates (roughly) to which production equipment, and how to adjust mixing times or speeds to account for equipment differences.

  2. mosunmola juliette adeniji

    The system that worked really well for me was practically avoiding having a full drum of production go bad.Every manufacturer no matter how small should have an equiped laboratory where you can digitally down size your formulations to the barest minimal to experiment with The new or slightly different colours or chemicals that you now have to produce with instead of the particular ones you were used to,.even if its only one chemical thats different out of twenty items you utilize, always standardize your formulations with the most minimal of your ingridients before going for a large batch.,

  3. trang

    hi Perry,

    Some people advise to add preservatives before neutralizing to prevent the pH increase too high at the contact site between the drop of preservative and product which could make the active of preservative at that site decrease. Is that right?

    Thanks for your advise!

  4. Gavanne

    I have experienced adding color at the beginning of the batch, and once it cools, the color appears very different than when it was heated. Is this normal? How do you guys make sure the final color is what you desire?

  5. Perry Romanowski

    lol – you guys crack me up. So sad that it’s mostly true.

  6. Rob

    9. Write clear guidelines on manufacturing when you hand over – because someone is bound to stuff it up and blame it on you. In the case of my old company email the relevant person and then CC EVERYONE else in the company so you have proof the stuff up wasn’t you.

    Or maybe I am being paranoid!

    1. Duncan

      No if it goes wrong they WILL be out to get you

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