Thickener Recommendations for Electrolyte-Tolerant Airless Pump Lotion
Question
Please recommend a thickener that:
Can be used with emulsifiers that do not give much body, such as silk lotion maker or glyceryl stearate citrate
Has good electrolyte tolerance, e.g. can be used with Active Protect OX, sodium PCA, sodium lactate and/or Zinc Pca
Can be used in the pH range 5-6
Gives a soft, smooth feel, is not tacky, and is not too viscous to use with an airless pump system (e.g. sepicmax zen, even at less than 0.5%, gives a feel that is too thick)
Cannot use xanthumgum, either the regular type or the slightly stretchy type, because from testing, the end product is still too runny and cannot be used with an airless pump (the pump does not dispense)
Answer
Recommended thickeners for this case:
| Priority | Product | Why it fits | Suggested starting level |
|---|---|---|---|
| 1 | ThixoGel™ (Thixotropic Gel Maker) | Best fit for airless pump systems because it is thick at rest but flows more easily when pumped. Catalog data: electrolyte resistant, pH 2–10, non-ionic, gives “thick but liquid” thixotropic gel. | Start 0.2–0.6%; increase gradually if more body is needed. Avoid using >1% at first because it can become too structured. Requires heat and continuous mixing; do not exceed 80°C. |
| 2 | Hydroxyethyl Cellulose (HEC) 2000mPa.s / 2800mPa.s | Non-ionic gel former, not affected by electrolytes, usable pH 3–9. Lower-viscosity grades are more suitable than 4500mPa.s when the target is pumpable lotion/serum. | Start 0.3–0.8%. Hydrate at about 70°C, then cool and adjust final pH. |
| 3 | Carbomer U20 (EasyDisperse, Electrolyte Tolerance) | Electrolyte-tolerant and pH 4–10, so it can work at pH 5–6. Gives more elegant slip than xanthan, but must be neutralized correctly. | Start 0.15–0.35% for airless-pump lotion; neutralize carefully to final pH 5.5–6.0. Avoid high dosage because it may become too thick. |
| 4 | Pudding Gel Maker™ (Acid/Electrolyte Resistant) | Very electrolyte/acid resistant and pH 2–9, but its design is for stronger gel/pudding texture. | Use only low level 0.2–0.5% if used for body-building. Higher levels may become too firm for pump packaging. |
Best practical recommendation: try ThixoGel™ 0.3–0.5% + HEC 2000mPa.s 0.2–0.4%. This combination should give more body than using Silk Lotion Maker or Glyceryl Stearate Citrate alone, tolerate electrolyte actives better than xanthan, and keep a flow profile more suitable for airless pumps than Sepimax Zen at similar perceived thickness.
Process notes
- Add the thickener to the water phase first and hydrate fully before adding high-electrolyte ingredients such as sodium PCA, sodium lactate, or Zinc PCA.
- Add electrolyte actives slowly after the gel network has formed; check viscosity again after 12–24 hours because polymers may continue hydrating.
- Keep final pH around 5.5–6.0 if using Carbomer U20, because carbomer structure depends on neutralization.
- For ThixoGel™ and HEC, heat processing is required. Keep ThixoGel™ below 80°C.
- Avoid high levels of Pudding Gel Maker™ or Pro Polymer™ if the goal is pumpable lotion, because these can move toward pudding-like texture at higher dosage.
For the stated target, I would not choose Sepimax Zen or xanthan as the main thickener. Sepimax Zen already gave too much viscosity in your test, while xanthan can give drag/stringiness or poor pump behavior depending on the system.
Related Products Mentioned
ThixoGel™ (Thixotropic Gel Maker)
