Adjusting Sulfate-Free Shampoo Formulation and Preservative Requirements
Question
I am formulating a shampoo with a total batch size of 150 ml. I have planned the following ingredients, but I realized the total percentage exceeds 100%. I would like to know how to correctly adjust this formula and whether I need to add an additional preservative or if the ones in the base are sufficient.
Current Formulation:
HairWash(Shampoo base): 93.2%Foam Built-in(fixative): 9.2%Silicone Water: 3%HairPLEX: 1.5%Bis-Aminopropyl Diglycol Dimaleate: 1%Pro-Vit(Panthenol): 1%Silk Protein: (Amount not specified)
Questions:
- How should I adjust these percentages to total 100%?
- Are
HairPLEXandBis-Aminopropyl Diglycol Dimaleatethe same ingredient? - Do I need to add a separate preservative for this 150 ml batch, or is the preservative already included in the
HairWashbase sufficient?
Answer
The formula you provided currently exceeds 100% (totaling approximately 108.9% excluding the Silk Protein), which means the proportions need to be adjusted. Additionally, HairPLEX™ and Bis-Aminopropyl Diglycol Dimaleate are the same ingredient (HairPLEX™ contains this substance at a 40% concentration), so they should be combined into one entry.
1. Formula Correction & Adjustment
To make a 150 ml (approximately 150 grams) batch, the percentages have been adjusted to total 100%. I have also included a preservative, which is necessary when adding natural proteins like Silk Protein.
| Ingredient | Percentage (%) | Amount for 150g (grams) |
|---|---|---|
| Sulfate Free Shampoo Base (HairWash) | 83.0% | 124.5 g |
| SweetWash™ Hair (Foam Built-in fixative) | 9.0% | 13.5 g |
| SiliWater™ (Silicone Water) | 3.0% | 4.5 g |
| HairPLEX™ (Bis-Aminopropyl Diglycol Dimaleate) | 2.5% | 3.75 g |
| D-Panthenol Care (Pro-Vit B5) | 1.0% | 1.5 g |
| Hydrolyzed Silk Protein | 0.5% | 0.75 g |
| Preservative (e.g., Phenoxyethanol SA) | 1.0% | 1.5 g |
| Total | 100% | 150 g |
2. About the Preservative
While the Sulfate Free Shampoo Base and SweetWash™ Hair already contain preservatives, they are formulated to protect the base itself. When you add a significant amount of "actives" (over 5-10%) and especially natural proteins like Hydrolyzed Silk Protein, the existing preservative system is diluted. Natural proteins are highly susceptible to microbial growth. Therefore, it is strongly recommended to add an additional 1% of a broad-spectrum preservative to ensure the shelf life and safety of your shampoo.
3. Mixing Instructions
- Prepare Actives: In a small container, mix the D-Panthenol Care, HairPLEX™, and SiliWater™.
- Dissolve Protein: Add the Hydrolyzed Silk Protein powder into the mixture from step 1 and stir until completely dissolved.
- Combine Bases: In a main mixing vessel, blend the Sulfate Free Shampoo Base and SweetWash™ Hair together gently to avoid creating excessive bubbles.
- Final Mix: Slowly pour the active mixture (from step 2) into the shampoo base. Stir gently until the texture is uniform.
- Add Preservative: Add the preservative last and stir well.
- Adjust Thickness: If the shampoo is too thin, you can add a small amount of salt (0.5-1.5%) to increase viscosity, as the Sulfate Free base is salt-responsive. Stir gently and let it sit for 24 hours to reach its final thickness.
Follow-up Replies
Question:
I am formulating a shampoo with a total batch size of 150 ml. I have planned the following ingredients, but I realized the total percentage exceeds 100%. I would like to know how to correctly adjust this formula and whether I need to add an additional preservative or if the ones in the base are sufficient.
Current Formulation:
HairWash(Shampoo base): 93.2%Foam Built-in(fixative): 9.2%Silicone Water: 3%HairPLEX: 1.5%Bis-Aminopropyl Diglycol Dimaleate: 1%Pro-Vit(Panthenol): 1%Silk Protein: (Amount not specified)
Questions:
- How should I adjust these percentages to total 100%?
- Are
HairPLEXandBis-Aminopropyl Diglycol Dimaleatethe same ingredient? - Do I need to add a separate preservative for this 150 ml batch, or is the preservative already included in the
HairWashbase sufficient? - In this formulation, there is no water; is it OK?
- The website mentions that this shampoo base needs an amphoteric surfactant (e.g., coco betaine), but I don't see it in this formulation. Should it be added?
Answer:
To address your questions regarding your shampoo formulation for a 150 ml batch:
1. Is it OK that there is no water?
No, it is not recommended to formulate without adding water.
Both the Sulfate Free Shampoo Base (pH 7, Clear, Foaming) and SweetWash™ Hair are concentrated surfactant systems.
- Sulfate Free Shampoo Base is recommended for use at 25-35% of the total formula, with the remainder being distilled water.
- SweetWash™ Hair specifically requires a 1:1 dilution with water (50% base to 50% water).
Using these bases at nearly 100% concentration will result in a product that is extremely harsh, potentially irritating to the scalp, and likely too thick to use effectively.
2. Amphoteric Surfactant (Coco-Betaine)
The Sulfate Free Shampoo Base already contains 12% Cocamidopropyl Betaine. However, when you dilute the base with water, the concentration of this surfactant drops. To ensure the shampoo thickens properly when adding salt and to increase foam creaminess, it is recommended to add an additional 2-4% of Coco-Betaine.
3. HairPLEX™ vs. Bis-Aminopropyl Diglycol Dimaleate
Yes, HairPLEX™ and Bis-Aminopropyl Diglycol Dimaleate are the same ingredient. HairPLEX™ is the trade name for this specific hair-bond-repairing substance. In your formula, you should combine these into a single entry.
4. Preservative Requirement
Yes, you must add a separate preservative.
While the bases contain preservatives to protect themselves, once you add a large amount of water and natural proteins like Hydrolyzed Silk Protein, the original preservative system is diluted and no longer sufficient. Adding 1% of a broad-spectrum preservative like Phenoxyethanol SA is essential for safety and shelf life.
5. Compatibility Warning
The manufacturer of SweetWash™ Hair advises against mixing it with other surfactant systems, as it may lead to instability. Since your original formula was primarily the Sulfate Free base, it is safer to use that as your primary cleanser.
Adjusted Formulation (150 ml / 150 grams)
This formula balances the ingredients to 100% and includes the necessary water and preservative.
| Ingredient | Percentage (%) | Amount for 150g (grams) |
|---|---|---|
| Distilled Water | 55.0% | 82.5 g |
| Sulfate Free Shampoo Base | 35.0% | 52.5 g |
| Coco-Betaine | 3.0% | 4.5 g |
| HairPLEX™ | 2.5% | 3.75 g |
| SiliWater™ | 1.5% | 2.25 g |
| D-Panthenol Care (Pro-Vit B5) | 1.0% | 1.5 g |
| Phenoxyethanol SA (Preservative) | 1.0% | 1.5 g |
| Hydrolyzed Silk Protein | 1.0% | 1.5 g |
| Total | 100% | 150 g |
Mixing Instructions:
- Dissolve Protein: Mix the Hydrolyzed Silk Protein powder into the Distilled Water and stir until completely dissolved.
- Add Actives: Add D-Panthenol Care, HairPLEX™, and SiliWater™ to the water phase. Stir well.
- Combine with Base: Slowly pour the Sulfate Free Shampoo Base and Coco-Betaine into the mixture. Stir gently to avoid creating excessive bubbles.
- Preserve: Add the Phenoxyethanol SA last and stir.
- Thicken: If the shampoo is too thin, add small increments of common salt (0.5-1.5% total) and stir gently. Let it sit for 24 hours to reach its final thickness.
Related Products Mentioned
SiliWater™ (silicone dissolved in water)
Phenoxyethanol SA (eq. Optiphen Plus)
