Formulation and Stability of Antiperspirant/Deodorant Base Cream (124994) for Roll-on Application
Question
I have questions regarding the Antiperspirant / Deodorant Base Cream (code: 124994):
- Are there any base alternatives in a lotion format available, besides the cream base?
- If a lotion base is not available, can I add water to the cream base to thin it for packaging in a roll-on bottle? If so, what is the recommended percentage of water addition? (I need to ensure stability for roll-on use.)
- Can the following ingredients be added to the Base Cream or a potential Base Lotion? Please provide advice on compatibility and mixing instructions for proper use:
- Aluminum Chlorohydrate 50% (Liquid)
- Aluminum Chlorohydrate 100% (Powder) - Please advise on the mixing method.
- Aluminum Zirconium Pentachlorohydrex GLY (Powder) - Please advise on the mixing method.
- Lauric acid
- Fragrance
- Microcare PHC
Answer
Thank you for your inquiry regarding the Antiperspirant / Deodorant Base Cream (124994). Here are the answers to your questions:
1. Is there a lotion base available besides the cream base?
Currently, we do not offer a dedicated Antiperspirant/Deodorant base in a liquid lotion format. The Antiperspirant / Deodorant Base Cream (124994) is the only base specifically designed for this purpose. Its texture is already light and quick-drying, making it suitable for underarm application.
2. Can water be added to the cream base to make it liquid for roll-on bottles? If so, what percentage?
We strongly advise against diluting the cream base with water for use in a roll-on bottle.
- The base is an emulsion (a mixture of oil and water) stabilized for a cream texture. Adding a large amount of water will destabilize the emulsion, causing the oil and water phases to separate.
- Furthermore, antiperspirant active ingredients (aluminum salts) are acidic. Adding them to an already unstable, diluted emulsion will almost certainly cause the product to break and separate.
Recommendation: The base (124994) is formulated for a cream or soft-solid stick application. If you require a roll-on product, you should use a liquid antiperspirant active (such as Aluminum Chlorohydrate 50% liquid) and formulate it with a suitable liquid base or a water/thickener system designed for roll-ons.
3. Can the listed ingredients be added to the base cream, and what are the mixing instructions?
Yes, all the listed ingredients can be added to the Antiperspirant / Deodorant Base Cream (124994).
| Ingredient | Compatibility | Recommended Usage Rate | Mixing Instructions |
|---|---|---|---|
| Aluminum Chlorohydrate (50% Liquid) | Yes | 10-15% | Add directly to the base and mix well until uniform. |
| Aluminum Chlorohydrate (100% Powder, e.g., Anti-Sweat™ 615) | Yes | 10-15% | Add the powder directly to the base cream and mix thoroughly with a high-shear mixer (if available) until the powder is completely dissolved/dispersed and the cream is uniform. |
| Aluminum Zirconium Pentachlorohydrex GLY (Powder, 35428) | Yes | 10-15% | Similar to Aluminum Chlorohydrate powder, add directly to the base and mix thoroughly with a high-shear mixer until completely dissolved/dispersed. |
| Lauric Acid (901) | Yes | 0.1-1.0% | Lauric acid is a solid. It must be melted first (around 44°C) and then mixed into the base cream. Start with a low concentration to avoid affecting the final texture. |
| Fragrance | Yes | 0.1-1.0% | Add the fragrance last, after all other active ingredients have been fully incorporated, and mix gently. |
| Microcare PHC (1438 eq.) | Yes | 0.5-1.0% | The base is preservative-free, so adding a preservative is essential. Add the preservative and mix well until uniform. |
General Mixing Order:
- Start with the Antiperspirant / Deodorant Base Cream (124994).
- Add the Aluminum-based active ingredient (powder or liquid) and mix well.
- Add the melted Lauric Acid (if used) and mix.
- Add Microcare PHC and mix.
- Add Fragrance and mix gently.
Ensure the final product is uniform before packaging.
Follow-up Replies
Question:
I am mixing aluminum salts (antiperspirant actives) into the Antiperspirant / Deodorant Base Cream (124994).
- Is it necessary to adjust the pH after incorporating these materials?
- If pH adjustment is required, should I use Triethanolamine or another substance?
Answer:
Regarding your question about pH adjustment after adding the aluminum salts to the Antiperspirant / Deodorant Base Cream (124994):
pH adjustment is generally NOT necessary and is strongly discouraged.
Why pH Adjustment is Not Recommended
- Stability and Efficacy: Aluminum-based antiperspirant active ingredients (like Aluminum Chlorohydrate and Aluminum Zirconium Pentachlorohydrex GLY) are most effective and stable in an acidic environment, typically with a pH range of 4.0 to 5.0.
- Risk of Precipitation: The base cream is formulated to be compatible with these acidic actives. If you use an alkaline substance like Triethanolamine (TEA) to raise the pH, it will cause the aluminum salts to hydrolyze and precipitate (fall out of the solution/dispersion). This will result in:
- Loss of antiperspirant efficacy.
- Product instability and separation.
Recommendation
- Measure the pH: After fully incorporating the aluminum active and other ingredients, measure the final pH of the cream.
- Ideal Range: The final pH should naturally fall within the effective range of 4.0 to 5.0.
- Do Not Use TEA: Do not use Triethanolamine or any other alkaline substance to increase the pH.
- If Adjustment is Necessary (Rare): If the pH is slightly too high (above 5.0, which is unlikely), you would use a mild acid like Citric Acid to lower it. However, in a properly formulated base designed for antiperspirants, this step is usually unnecessary.
Related Products Mentioned
Lauric Acid (99%)
Aluminum Zirconium Pentachlorohydrex GLY
