This formulation base utilizes Hallstar’s elegant sunscreen solvent and emollient HallBrite® BHB to optimize solvent polarity. Triplet state-quenching polymeric photostabilizer Polycrylene® has been added, providing substantial additional photostabilization to the composition.
In vivo testing (five subjects) indicates static SPF 31, while in vitro testing suggests PFA (PPD) ~ 10. Critical wavelength = 378 nm.
The resulting sunscreen cream is Octinoxate-, Oxybenzone-, and Octocrylene-free — a great example of how the right ingredients allow sun care formulators to create appealing, effective products within today’s environmental and regulatory limitations.
| Phase | INCI Name [INN/USAN] (Other Information) | Trade Name | % Wt | Function |
|---|---|---|---|---|
| A | Homosalate [Homosalate] | 7.00 | UV Filter / Sunscreen Agent | |
Butyloctyl Salicylate | HallBrite® BHB* | 5.00 | Sunscreen Solvent | |
| C12-15 Alkyl Benzoate | 4.00 | Sunscreen Solvent | ||
Polyester-8 | Polycrylene®* | 4.00 | Photostabilizer | |
| B | Butyl Methoxydibenzoylmethane [Avobenzone] | 3.00 | UV Filter / Sunscreen Agent | |
| C | VP/Eicosene Copolymer | 1.00 | Film Former | |
Glyceryl Stearate | HallStar® GMS Pure | 0.90 | Emulsifier | |
PEG-100 Stearate | HallStar® PEG 4400 MS MB | 0.80 | Co-emulsifier | |
Cetearyl Alcohol | HallStar® TA-1618 Cetearyl Alcohol | 0.50 | Thickener (Nonaqueous) | |
| Potassium Cetyl Phosphate, Hydrogenated Palm Glycerides | 2.20 | Emulsifier | ||
| D | Styrene/Acrylates Copolymer (hollow spherical, 325 nm) | 3.00 | SPF Booster | |
| E | Water (Aqua) | up to 100 | Volatile Carrier | |
| Glycerin | 3.00 | Humectant | ||
| Disodium EDTA | 0.05 | Chelating Agent | ||
| Xanthan Gum (pharma grade) | 0.20 | Thickener (Aqueous) | ||
| F | Caprylyl Glycol, Phenoxyethanol, Hexylene Glycol | 0.60 | Preservative | |
| Acrylamide/Sodium Acryloyldimethyltaurate Copolymer, Isohexadecane, Polysorbate 80 | 1.50 | Thickener (Aqueous) / Emulsion Stabilizer | ||
| Silica (spherical, 12 µm) | 2.00 | Deoiling Agent |
PREPARATIVE PROCEDURE
| 1 | To a secondary vessel add phase A and start mixing. Add phase B and heat to 80°C and then add phase C. Before combining with water, add phase D and mix well. |
| 2 | To the main vessel add liquids of phase E, start mixing and add remaining phase items in order. |
| 3 | When solids of phase E are fully incorporated, heat phase to 75°C. |
| 4 | When both phases are homogeneous and at their designated temperatures, slowly add phase ABCD to phase E with prop mixing. |
| 5 | Start homogenizing phase ABCDE for 3 minutes, then switch to center mixing. |
| 6 | Start cooling batch and when batch is < 50°C add phase G items one by one with mixing. |
| 7 | Continue mixing until batch is at room temperature, replacing any water lost to evaporation and mixing until smooth. |
PRODUCT CHARACTERISTICS (25°C)
| Appearance | Off-white cream |
| Viscosity (20 rpm, Brk, RV DV-II, T-D, after 24h at room temperature; mPa∙s) | 12000 - 20000 |
| pH (as is) | 5.5 - 6.5 |
*Patented and Patent Pending
The information presented herein is believed to be accurate and reliable, but no warranty or guarantee, expressed or implied, is made regarding the information or the performance of any product. Further, nothing contained herein shall be taken as any inducement or recommendation to use, manufacture or sell that may infringe any patents or any other proprietary rights now or hereafter in existence, nor to imply compliance with any regulatory requirements
The Hallstar Company - 120 South Riverside Plaza Suite 1620 - Chicago, IL 60606-3911 USA hallstarbeauty.com