Toner Formula for Removing Post-Cleansing Residue on Combination Acne-Prone Skin

Question

May I ask for advice on a toner formula to remove residue after washing the face?

Ingredients

N-Acetyl Cysteine (สังเคราะห์ Glutathione) 5%
สารสกัด มะเขือเทศ 5%
Creatine 100 1%
MOIST24 3%
Mild Preserved Eco™ (Preservative-Free) 1%
Polysorbate 20 (Tween 20) 2%
น้ำหอม0.5%
EDTA 0.2%
Allantoin0.3%
DI Water ในส่วนที่เหลือ ครบ100%

Questions:

Can this formula remove various residues after washing the face? (Pour onto cotton pad and wipe off after washing the face)
What should the pH be?
Overall, is this formula suitable for combination, acne-prone skin, for regular morning and evening use?
Will the toner feel sticky after use?
Can it be used together with other anti-wrinkle serums?
If the formula is not suitable, please help adjust the formula and advise on the mixing procedure.

Answer 1

Summary: The formula is more suitable as a wipe-off / leave-on hydrating antioxidant toner, not a true cleansing water. It can help remove some post-cleansing residue mainly through the mechanical wiping action of the cotton pad, with some help from Polysorbate 20, but it should not be positioned as a main makeup/sunscreen remover or as a formula that removes all residue completely.

Formula review

Ingredient	Comment
N-Acetyl Cysteine (Glutathione Precursor) 5%	Within the catalog maximum, but this is the high end. It may affect odor, acidity, skin feel and irritation risk. For a daily AM/PM toner, start testing at 2–3% first unless 5% is specifically needed and passes stability/sensory testing. Avoid heat, air and light.
Tomato Natural Water Soluble Color / Tomato Extract 5%	Not recommended at 5% if using this catalog material. Catalog range is 0.1–1%; reduce to 0.1–0.5%, or not over 1%. 5% may give strong color, heavier feel, instability and higher preservation burden.
Creatine 100 1%	Suitable; within catalog range and compatible with the suggested pH.
MOIST24 3%	Usable, but for combination/acne-prone skin and a light toner feel, reduce to 1–2% if stickiness is a concern.
Mild Preserved Eco™ 1%	Within range. For a high-water formula with natural extract, perform a preservative efficacy/challenge test before selling; if needed, adjust within the catalog range.
Polysorbate 20 2% + fragrance 0.5%	Technically can help solubilize fragrance, but may add afterfeel/foam. For acne-prone skin, fragrance 0–0.1% or fragrance-free is preferred. Polysorbate 20 trial range: about 0.3–1.0% if fragrance-free/for slight residue-lifting support, or 1–2% only as needed to solubilize fragrance, then check clarity and separation.
Disodium EDTA 0.2%	Suitable; add into water first.
Allantoin 0.3%	Suitable, but must be fully dissolved; keep within room-temperature solubility limits.

Recommended pH

Target final pH: 4.8–5.0
Acceptable practical window: about 4.5–5.2. This fits the overlap of N-Acetyl Cysteine, Creatine 100, Mild Preserved Eco™, Allantoin, Disodium EDTA and MOIST24 better than a higher-pH toner.

Suggested trial formula

Use this as a starting trial, not a proven final commercial formula:

DI Water: q.s. to 100%
Disodium EDTA: 0.2%
Allantoin: 0.2–0.3%
Creatine 100: 1.0%
N-Acetyl Cysteine: 2–3% to start; use 5% only if the odor, pH, skin feel and stability are acceptable
MOIST24: 1–2%
Tomato Natural Water Soluble Color / Tomato Extract: 0.1–0.5%, not over 1%
Mild Preserved Eco™: 1.0–1.5%
Polysorbate 20: about 0.3–1.0% if fragrance-free / for slight residue-lifting support; 1–2% only as needed if fragrance is used
Fragrance: preferably 0%, or very low at 0–0.1%

Mixing procedure

Add DI Water to the main vessel at room temperature, or warm gently to not over about 40°C.
Add Disodium EDTA and mix until dissolved.
Add Allantoin and mix until fully dissolved and clear.
Add Creatine 100 and mix until dissolved.
Add MOIST24 and mix until uniform.
Add the reduced level of Tomato Natural Water Soluble Color / Tomato Extract and mix until uniform.
Add N-Acetyl Cysteine near the end; avoid heat, excessive air incorporation and strong light.
If using fragrance, premix fragrance + Polysorbate 20 until uniform/clear, then add to the water phase. Check for cloudiness, separation and odor after aging.
Add Mild Preserved Eco™ near the final stage and mix well.
Adjust pH to 4.8–5.0, top up DI Water to 100%, mix gently, filter coarsely if needed, and pack in a tightly closed, light-protective container.
Recheck pH after finishing and again after 24 hours, because N-Acetyl Cysteine and extracts may cause pH drift.

Use with acne-prone combination skin and anti-wrinkle serum

The original formula may feel sticky/filmy, especially from N-Acetyl Cysteine 5%, tomato extract 5%, MOIST24 3%, Polysorbate 20 2% and fragrance 0.5%.
It can generally be used with anti-wrinkle serums if the toner pH is around 4.8–5.2 and the skin does not sting or irritate. Let the toner dry first.
Be more cautious when pairing with AHA/BHA, retinoid or low-pH vitamin C serums; patch test first before using twice daily.

Testing before sale

For commercial production, perform:

Stability testing at room temperature, 40–45°C, freeze-thaw and light exposure.
Monitor color, odor, pH, clarity, precipitation, separation and microbial quality.
Preservative efficacy / challenge test, especially because this is a high-water formula with natural extract and is used with cotton pads.