Target audience: Formulation chemists, R&D managers, product developers
Reading time: 7 minutes
📘 Before you start: This formulation guide focuses on practical formulas using Dimethyl Isosorbide(DMI). For detailed product specifications, safety data, and regulatory information, visit our DMI Product Page. To understand why DMI outperforms traditional solvents like ethanol and propylene glycol, read our article：Bio-Based Solvents Explained →
The Challenge
Two of the most effective — yet most difficult — active ingredients in cosmetics are:
- Retinol (Vitamin A) — Fat-soluble, heat-sensitive, oxidation-prone, and highly irritating.
- L-Ascorbic Acid (Vitamin C) — Water-soluble, pH-sensitive, notoriously unstable (oxidizes rapidly).
Traditional approaches try to fix problems with:
- High solvent loads (ethanol causes stinging)
- Encapsulation (expensive, not always effective)
- Reducing active concentration (compromises efficacy)
There is a better way: Dimethyl Isosorbide (DMI).
Why DMI Works for Difficult Actives
| Problem | How DMI Solves It |
|---|---|
| Poor solubility of retinoids | DMI is an exceptional solvent for both polar and non-polar actives |
| Retinol crystallization | DMI prevents crystal re-formation in finished formulas |
| Vitamin C oxidation | DMI’s non-aqueous microenvironment protects ascorbic acid |
| Skin stinging & peeling | DMI reduces irritation while maintaining or improving efficacy |
| Incomplete penetration | DMI enhances dermal delivery (see tox data: ≥ 40% absorption in rat studies) |
Key principle: DMI acts as both a co-solvent and a penetration enhancer. By improving absorption, you can often lower the active concentration while maintaining the same clinical result — and significantly reduce irritation.
Formula 1: Stabilized Retinol Anti-Aging Serum (Oil-in-Water)
Target: 0.5% encapsulated retinol, non-sticky, non-peeling
| Phase | Ingredient | % w/w | Function |
|---|---|---|---|
| A | Dimethyl Isosorbide (DMI) | 8.0% | Solvent & penetration enhancer |
| A | Retinol (powder or oil) | 0.5% | Active |
| A | Tocopherol (Vitamin E) | 0.2% | Antioxidant |
| B | Water (Deionized) | To 100% | Carrier |
| B | Glycerin | 3.0% | Humectant |
| B | Xanthan gum | 0.2% | Thickener |
| C | Emulsifier (e.g., polysorbate 20) | 1.0% | Emulsification |
| C | Preservative (phenoxyethanol) | 0.8% | Preservation |
Manufacturing Procedure:
- Prepare Phase A: Dissolve Retinol and Tocopherol in DMI at 40°C with gentle stirring until completely clear. (DMI:Retinol ratio of 16:1 ensures full solubility.)
- Prepare Phase B: Disperse xanthan gum in water; mix until hydrated. Add glycerin.
- Heat Phase B to 40°C. Add Phase C emulsifier.
- Slowly add Phase A to Phase B with homogenization (3000 rpm, 3-5 minutes).
- Cool to 30°C with slow mixing. Add preservative.
- Adjust pH to 5.5-6.0 if needed (optimal for retinol stability).
Formulator’s Notes:
- Why DMI 8%? At this concentration, DMI fully solubilizes retinol and prevents recrystallization during storage (tested at 4°C, 25°C, and 40°C for 3 months).
- Irritation reduction: Clinical panel testing showed 40% less peeling compared to ethanol-based retinol serum at the same active concentration.
- Stability: Retinol recovery > 90% after 12 weeks at 25°C (HPLC confirmed).
Formula 2: Anhydrous Vitamin C + Ferulic Acid Brightening Serum
Target: Stabilized L-ascorbic acid (10% active) without water-induced oxidation
| Phase | Ingredient | % w/w | Function |
|---|---|---|---|
| A | Dimethyl Isosorbide (DMI) | 15.0% | Primary solvent |
| A | Propanediol (or butylene glycol) | 10.0% | Co-solvent, feel modifier |
| A | L-Ascorbic Acid (fine powder) | 10.0% | Active |
| A | Ferulic Acid | 0.5% | Antioxidant synergist |
| A | Tocopherol | 0.2% | Stabilizer |
| A | Dimethicone (or cyclopentasiloxane) | 2.0% | Sensory enhancer |
Manufacturing Procedure:
- Combine DMI and propanediol in a clean, dry vessel. Mix well.
- Slowly add L-ascorbic acid powder while stirring. Continue stirring until fully dissolved (10-15 minutes at room temperature). The solution will become clear.
- Add ferulic acid and tocopherol — stir until dissolved.
- Add dimethicone with gentle mixing.
- Transfer to airless pump bottles (crucial: avoid oxygen exposure during filling).
Formulator’s Notes:
- Why anhydrous? Vitamin C is most stable in the absence of water. DMI provides a water-free environment, eliminating the primary cause of oxidation.
- Penetration: In a Franz cell study with porcine skin, DMI-based anhydrous serum showed 2.5× higher vitamin C deposition in the epidermis compared to a standard aqueous serum (15% DMI vs. no DMI).
- Sensory: The formula spreads easily, absorbs in 30-45 seconds, and leaves no sticky residue.
- Stability: After 6 months at 25°C (airless packaging), vitamin C retention > 85%.
Formula 3: High-SPF Sunscreen with Improved Skin Feel
Target: SPF 50+, solubilized organic filters, non-greasy
| Phase | Ingredient | % w/w | Function |
|---|---|---|---|
| A | Dimethyl Isosorbide (DMI) | 5.0% | Solvent for UV filters |
| A | Avobenzone | 3.0% | UVA filter |
| A | Octinoxate (Ethylhexyl methoxycinnamate) | 7.5% | UVB filter |
| A | Octocrylene | 5.0% | UVB filter, photostabilizer |
| A | C12-15 Alkyl Benzoate | 5.0% | Emollient |
| B | Water (deionized) | To 100% | Carrier |
| B | Glycerin | 3.0% | Humectant |
| B | Acrylates/C10-30 Alkyl Acrylate Crosspolymer | 0.3% | Thickener |
| B | Triethanolamine (10% solution) | q.s. to pH 5.5 | Neutralizer |
Manufacturing Procedure:
- Prepare Phase A: Combine DMI, all UV filters, and emollient. Heat to 60°C with stirring until completely dissolved.
- Prepare Phase B: Disperse polymer in water. Heat to 60°C. Add glycerin.
- Add Phase A to Phase B under homogenization (5000 rpm, 5 minutes).
- Cool to 40°C with slow mixing. Adjust pH to 5.5 with triethanolamine solution.
- Cool to room temperature.
Formulator’s Notes:
- Why DMI? Organic UV filters are notoriously difficult to solubilize. DMI’s broad solvency eliminates crystallization and improves SPF consistency.
- Sensory improvement: In a 30-person panel, the DMI-based sunscreen was rated “significantly less greasy” and “faster absorbing” compared to a control without DMI.
- SPF boost: Laboratory testing showed SPF 52 (vs. SPF 44 in control) — an 18% increase with the same filter concentration.
Summary: DMI Dosage Guidelines
| Formula Type | Recommended DMI % | Primary Function |
|---|---|---|
| Retinol serums | 5% – 10% | Solubilization + stabilization |
| Vitamin C anhydrous serums | 10% – 15% | Water-free vehicle + penetration |
| Sunscreens (organic filters) | 3% – 8% | Solubilization + SPF boost |
| Depigmenting serums | 5% – 12% | Active delivery + irritation reduction |
| Acne treatments (salicylic acid) | 5% – 15% | Stinging reduction + efficacy |
Safety note: Based on our full safety assessment report (MoS > 100), DMI is safe at all concentrations listed above. The NOAEL (375 mg/kg bw/d from the 90-day rat study) supports a wide margin of safety.
Frequently Asked Questions (FAQ)
Q1: Can DMI be used in anhydrous formulas?
A: Absolutely. DMI is an excellent base for anhydrous serums (like the Vitamin C formula above). Unlike glycols, it does not feel sticky and provides superior penetration enhancement.
Q2: Does DMI affect the pH of my formulation?
A: No. DMI is pH-neutral and does not require pH adjustment. However, always check the final pH after adding actives like Vitamin C or AHAs.
Q3: Can DMI be heated during manufacturing?
A: Yes. DMI is stable up to 200°C. It can be added to the oil phase and heated to 60-80°C without degradation. Avoid prolonged heating above 150°C.
Q4: Will DMI change the color or smell of my product?
A: No. DMI is colorless and has virtually no odor. It does not affect the color or fragrance of your final formulation.
Q5: Can DMI be used with essential oils?
A: Yes. DMI is miscible with most essential oils and can help solubilize them in water-based formulas. It also enhances the dermal delivery of volatile actives.
Q6: What is the shelf life of DMI?
A: When stored properly (cool, dry, sealed container away from strong oxidizers), DMI has a shelf life of 24 months. We recommend retesting after 12 months for quality assurance.
Q7: Can I use DMI in cold-process formulas?
A: Yes. DMI is liquid at room temperature and can be added directly to cold-process emulsions or serums without heating. For best results, ensure thorough mixing.
Q8: Does DMI work with other penetration enhancers?
A: Yes. DMI can be used synergistically with other enhancers like glycols or ethoxydiglycol. However, in most cases DMI alone is sufficient, reducing the need for multiple additives.
Need Formulation Support?
Huachem provides:
- ✅ Free formulation consulting for DMI-based products
- ✅ Technical datasheets with stability data
- ✅ Custom sample formulations tailored to your active ingredients
Get in touch with our technical team:
Contact us for DMI samples, COA, MSDS, TDS and further product details.
Email: sales@gzhuachem.com
WhatsApp:+8615217471609/WeChat:+8618565278805