Overview
HPSIL® is the East Materials brand of pharmacopoeia and food-grade precipitated silica — purpose-engineered amorphous SiO₂ for regulated end markets where heavy-metal, microbial, and residue limits matter as much as functional performance.
Unlike the HJSIL® fumed silica family (flame hydrolysis, non-porous, industrial chemistry), HPSIL is produced by the wet-route precipitation process: sodium silicate acidified at controlled pH/temperature, generating porous particles whose internal pore network defines functional behaviour by application category. Wet-route control delivers tight specs on particle size, oil absorption, pH, and heavy-metal residue — all critical for regulated healthcare end uses.
The portfolio is organised by application category, not single grade codes:
- Toothpaste-grade silica — dental abrasive (RDA 30–150), thickener, and opacifier
- Food-grade silica (E 551 / FDA 21 CFR 172.480) — anti-caking in food powders, spices, dairy powder, table salt
- Pharmaceutical-grade silica (USP/NF, EP, JP, ChP) — tablet flow control, disintegrant, API liquid-to-solid carrier
- Cosmetic-grade silica — sebum control / mattifier for foundation, BB cream, sunscreen
See HJSIL® Fumed Silica for non-porous flame-hydrolysis grades, or MEGEL® Silica Aerogel for thermal-insulation forms.
Why a Separate Healthcare Silica Hub
Regulated healthcare markets impose constraints absent from industrial silica:
| Constraint | Detail |
|---|---|
| Pharmacopoeia compliance | USP/NF (US), EP (EU), JP (Japan), ChP (China) — each specifies independent limits for heavy metals, microbial bioburden, particle size, loss on drying, identification. One batch may ship with 4 compliance certificates. |
| FDA 21 CFR registration | Synthetic amorphous silica registered under 21 CFR 172.480 (direct food contact, anti-caking ≤2%) and 21 CFR 175.300 (indirect, food packaging). |
| Heavy-metal limits | Pharmacopoeia limits ~10× tighter than industrial silica. Typical: Pb ≤1 ppm, As ≤1 ppm, Cd ≤0.5 ppm, Hg ≤0.5 ppm. Industrial fumed silica routinely exceeds these. |
| GMP manufacturing | ISO 22716 (Cosmetics GMP), FAMI-QS (Feed GMP), ICH Q7 (API GMP). Plant must be physically segregated from industrial-grade lines. |
| End-product regulatory burden | US toothpaste = FDA cosmetic; EU = EFSA Cosmetics 1223/2009; China = NMPA. Supplier documentation chain enables end-product registration. |
East Materials supplies the full documentation package — REACH, FDA 21 CFR 172.480 declaration, USP/NF / EP / JP / ChP compliance certificates, EU 1333/2008 conformity, heavy-metal batch CoA.
Toothpaste-Grade Silica — Three Functions
A premium toothpaste typically uses three silica functions simultaneously: abrasive (polish), thickener (rheology), opacifier (visual). The three are NOT interchangeable.
Dental Abrasive
Particle size 5–15 μm with controlled mechanical hardness; clears plaque, stain, and tartar without enamel damage. The procurement metric is RDA (Relative Dentin Abrasivity) per ISO 11609.
| RDA Range | Classification | Use |
|---|---|---|
| <40 | Low / Sensitive | Sensitive and children's pastes |
| 40–100 | Standard | Mass-market daily toothpaste |
| 100–150 | Premium / Whitening | Whitening, mass-market premium |
| 150–250 | Maximum / ADA limit | Aggressive whitening, professional |
| >250 | NOT ACCEPTABLE | Damages enamel (ADA + ISO 11609 ceiling) |
East Materials supplies toothpaste-grade abrasives calibrated across the full RDA 30–150 band — RDA 30 (sensitive / baby tooth), RDA 60 (mass-market daily), RDA 100 (whitening standard), RDA 150 (premium / professional). Reference benchmarks: Evonik Sident 22 S, Sident 9, Sident 22, Sident 28. Recommended loading 15–25%; disperse on planetary mixer 30+ min after surfactant + humectant pre-blend, avoid high-shear blade mixers (break particle integrity).
Dental Thickener
Particle size 1–5 μm, high oil absorption, low RDA — builds the hydrogen-bonded thickener network without abrasive function. Three oil-absorption tiers: 110, 180, 250 mL/100 g. Reference benchmarks: Evonik Sipernat 320 / Sipernat 320 P, J.M. Huber Zeodent 165.
The 180 mL/100 g tier is RI-matched (≈ 1.45) for transparent gel toothpaste aligned with glycerin/sorbitol humectant phase. Loading 4–8% by target viscosity; add to wet phase under medium shear.
Dental Opacifier
Particle size 0.5–2 μm, high optical scatter cross-section; generates the white opaque visual independent of abrasive and thickener. Loading 0.5–2% at final mixing stage.
Example Recipe — Premium Whitening Toothpaste (RDA ~120)
| Ingredient | % w/w |
|---|---|
| Glycerin (humectant) | 22.0 |
| Sorbitol 70% solution | 25.0 |
| Water | 18.5 |
| Toothpaste-grade abrasive (RDA 100) | 18.0 |
| Toothpaste-grade thickener (180 mL/100 g) | 6.0 |
| Toothpaste-grade opacifier | 1.5 |
| Sodium fluoride | 0.32 |
| Sodium lauryl sulphate | 1.5 |
| Flavour + sweetener | 1.2 |
| Preservative | 0.1 |
| Colorant + minor | 0.38 |
| Sodium saccharin | 0.5 |
| Total | 100.0 |
Food-Grade Silica
Free-flow additive for spice powder, dairy creamer, salt, sugar, instant coffee, infant formula. Loading 0.2–2.0% on host powder; creates moisture barrier breaking inter-particle capillary bridges. Mix on V-blender or ribbon blender 20–30 min; for salt/sugar tableting, add at milling stage.
| Variant | Particle size (μm) | Oil absorption (mL/100g) | Carrier capacity (g host / g silica) | Reference / regulation |
|---|---|---|---|---|
| Food-grade, synthetic amorphous (standard) | 3–7 | 240 | 50 (typical spice) | E 551 / FDA 21 CFR 172.480 / Evonik Sipernat 22 S / Cabot Cab-O-Sil M-5 |
| Food-grade, coarse (FCC) | 7–14 | 220 | 30 (coarse spice, salt grinder) | Codex Stan 192/2013 |
| Food-grade, hydrophobic | 3–7 | 280 | 75 (humid / tropical storage) | Specialty, ambient RH >70% |
Regulatory: EU E 551 (silicon dioxide, synthetic amorphous), permitted as anti-caking agent at quantum satis. EFSA 2017 re-evaluation (EFSA-Q-2011-00746) reaffirmed safety. China GB 2760 permits up to 2%. Particle size 3–7 μm is well above EFSA's 2018 nanoparticle labelling threshold (<100 nm).
Pharmaceutical-Grade Silica
Tablet flow control and disintegrant in oral solid dosage; also liquid-to-solid carrier for API. Manufactured under ICH Q7 GMP; batch CoA per the relevant pharmacopoeia monograph.
| Function | Loading | Notes |
|---|---|---|
| Flow modification | 0.1–0.5% | Reduces inter-particle friction; enables higher tablet press line speed |
| Anti-caking in hopper | 0.1–0.5% | Prevents bridging in tablet feed |
| Disintegrant | 1–5% | High water uptake promotes tablet breakup in gastric fluid |
| Liquid-to-solid carrier (API) | 10–30% | High oil absorption holds liquid API in flowable solid |
Pharmacopoeia variants — USP/NF, EP, JP — share particle size 5–10 μm, oil absorption ~200 mL/100 g, pH 5.5–7.5, and reference Evonik Aerosil 200P in NF / EP / JP grades. Each batch CoA includes:
- Identity (IR / ICP-MS / pH)
- Loss on drying ≤6.0%; loss on ignition ≤8.0%
- Lead ≤1.0 ppm (USP/NF), ≤2.0 ppm (EP); total heavy metals ≤10 ppm (USP)
- pH (5% slurry) 4.0–8.0
- Microbial bioburden (USP <61> aerobic + USP <62> specified)
BSE/TSE-free statement, DMF/ASMF reference, and master batch record available on request.
Cosmetic-Grade Silica
Mattifier in foundation, BB cream, sunscreen, oil-control primer; loading 1–4%. Functions: sebum absorption (matte appearance), soft-focus (diffuse-reflection of pore/wrinkle shadows), dry-touch powder feel, anti-shift wear duration.
| Variant | Particle size (μm) | Oil absorption (mL/100g) | Use | Reference |
|---|---|---|---|---|
| Cosmetic-grade, daily wear | 3–7 | 200 | Standard sebum control, daily foundation | Evonik Sipernat 50S |
| Cosmetic-grade, intensive oil control | 2–5 | 380 | Sport / sweat-resistant makeup | (specialty) |
Manufactured under ISO 22716 (Cosmetic GMP). Heavy-metal CoA at cosmetic-grade limits (Pb ≤1 ppm, As ≤1 ppm, Cd ≤0.5 ppm, Hg ≤0.5 ppm). EU Cosmetics Regulation 1223/2009 Annex II compliance verified.
Specification Summary — All Categories
| Category | Function | Particle size (μm) | Oil absorption (mL/100g) | Loading | Reference benchmark |
|---|---|---|---|---|---|
| Toothpaste-grade abrasive | Polish active (RDA 30–150) | 5–14 | 70–110 | 15–22% | Evonik Sident 22 S / 9 / 22 / 28 |
| Toothpaste-grade thickener | Paste rheology | 1–5 | 110 / 180 / 250 | 4–8% | Evonik Sipernat 320 / 320 P, Zeodent 165 |
| Toothpaste-grade opacifier | White visual | 0.5–2 | n/a | 0.5–2.5% | (specialty) |
| Food-grade (standard) | Anti-caking | 3–7 | 240 | 0.2–2.0% | Sipernat 22 S / Cab-O-Sil M-5 |
| Food-grade (coarse) | Coarse spice / salt | 7–14 | 220 | 0.2–2.0% | Codex Stan 192/2013 |
| Food-grade (hydrophobic) | Tropical-climate storage | 3–7 | 280 | 0.2–2.0% | (specialty) |
| Pharma-grade USP/NF | Flow / disintegrant | 5–10 | 200 | 0.1–5% (30% carrier) | Aerosil 200P (NF) |
| Pharma-grade EP | Flow / disintegrant | 5–10 | 200 | 0.1–5% | Aerosil 200P (EP) |
| Pharma-grade JP | Flow / disintegrant | 5–10 | 200 | 0.1–5% | Aerosil 200P (JP) |
| Cosmetic-grade (daily) | Sebum control | 3–7 | 200 | 1–4% | Sipernat 50S |
| Cosmetic-grade (intensive) | Sweat-resistant matt | 2–5 | 380 | 1–4% | (specialty) |
Selection Guide
| Use case | Recommended category combination |
|---|---|
| Sensitive / children's toothpaste | Toothpaste abrasive (RDA 30) |
| Mass-market daily toothpaste | Toothpaste abrasive (RDA 60) + thickener (110) |
| Whitening toothpaste | Toothpaste abrasive (RDA 100) + thickener (180) + opacifier |
| Premium whitening / professional | Toothpaste abrasive (RDA 150) + thickener (180) + opacifier (high) |
| Transparent gel toothpaste | Toothpaste thickener (180), RI-matched |
| Food anti-caking (spice / salt / dairy) | Food-grade standard or coarse |
| Food anti-caking, tropical / humid | Food-grade hydrophobic |
| Pharma tablet flow control | Pharma-grade (USP/NF / EP / JP per market) |
| Pharma disintegrant | Pharma-grade USP/NF at 3–5% |
| Liquid-to-solid carrier (API) | Pharma-grade USP/NF at 10–30% |
| Daily wear foundation | Cosmetic-grade daily |
| Sport / oil-control makeup | Cosmetic-grade intensive |
Procurement, Storage, and QC
| Pack format | MOQ | Lead time (FOB Shanghai) |
|---|---|---|
| 5 kg PE-lined kraft (lab) | 1 bag (pharma) / 5 bags (cosmetic, food) | 4–5 wk |
| 15 / 25 kg PE-lined paper | 1 pallet (1.0–1.2 t) | 4–6 wk |
| 250 kg FIBC big-bag | 4 t (1 container × 16 bags) | 4–6 wk |
| Pharmaceutical grade (USP/NF / EP / JP) | 1 pallet | 6–8 wk (additional batch testing) |
| Cosmetic-grade variants | 1 pallet | 4–5 wk |
Sealed dry storage <25°C. Hydrophilic variants adsorb atmospheric moisture; decant into sealed container after opening or use within 60 days. Shelf life: standard grades 24 months sealed / 6 months opened; hydrophobic food variant 18 months sealed.
Every-batch CoA includes: identification (IR / ICP-MS / XRD), loss on drying & ignition, pH (5% slurry, USP <791>), heavy metals (Pb / As / Cd / Hg), bioburden (USP <61> + <62>, pharma and cosmetic), particle size distribution (laser diffraction, ISO 13320), oil absorption (DBP, ISO 19246), RDA test report (ISO 11609, dental on request).
Regulatory documentation by end market:
| End market | Documentation provided |
|---|---|
| US toothpaste / cosmetic | FDA cosmetic registration, 21 CFR compliance |
| EU toothpaste / cosmetic | EU 1223/2009, ISO 22716 GMP |
| China toothpaste | NMPA Cosmetic Registration, GB 22115 |
| Japan toothpaste | PMDA Cosmetic Notification (on request) |
| US food | FDA 21 CFR 172.480 declaration, GRAS letter |
| EU food | EU 1333/2008 E 551 conformity, EFSA dossier |
| China food | GB 2760, GB 25576 |
| US pharma | USP/NF Silicon Dioxide monograph, BSE/TSE-free statement |
| EU pharma | EP monograph, ASMF / DMF (on request) |
| Japan pharma | JP monograph, Japanese DMF (on request) |
FAQ
Is HPSIL the same as Evonik Sident / W.R. Grace SYLOID / J.M. Huber Zeodent?
Functionally yes. HPSIL is engineered to match the RDA, particle size, oil absorption, and purity targets of the corresponding Evonik Sident, W.R. Grace SYLOID, and J.M. Huber Zeodent reference grades. Independent third-party RDA testing confirms HPSIL whitening-grade abrasive within ±5 RDA points of Evonik Sident 22 in standard toothpaste formulation. Landed cost differential 30–45%.
What's the difference between dental abrasive, thickener, and opacifier?
Function and particle size. Abrasive (5–15 μm) provides RDA-controlled mechanical plaque removal at 15–25% loading. Thickener (1–5 μm) provides paste rheology with low RDA at 4–8% loading. Opacifier (0.5–2 μm) provides white visual at 0.5–2% loading. Not interchangeable — premium toothpaste uses all three simultaneously.
Can HPSIL be used in EU foods? What pharmacopoeia documentation is included?
EU food: yes — food-grade variants are E 551 compliant per EU 1333/2008; EFSA 2017 re-evaluation reaffirmed safety. Particle size 3–7 μm is far above EFSA's 2018 nano labelling threshold. Pharma: each pharma-grade shipment includes batch CoA per the relevant monograph (USP/NF, EP, JP) covering identity, loss on drying/ignition, pH, heavy metals, residuals, bioburden, and particle size. BSE/TSE-free statement and DMF reference on request.
What is the typical RDA of premium whitening toothpaste?
ADA maximum and ISO 11609 ceiling: 250 RDA. Real-world premium whitening targets 80–180 RDA; heavy clinical whitening up to 250; sensitive pastes 30–50. Final RDA depends on abrasive grade selection, loading (typically 15–25%), and co-formulation with thickener silica. East Materials can perform indicative RDA testing on customer prototype formulations on request.
What is the typical lead time and MOQ?
Standard dental and food: 4–6 weeks FOB Shanghai, MOQ 1 pallet (1.0–1.2 t). Pharmaceutical: 6–8 weeks (additional batch testing). Cosmetic: 4–5 weeks. 5 kg lab samples available for pharma/cosmetic qualification.
How is cross-contamination with industrial silica prevented?
Healthcare grades are produced on a physically separated manufacturing line, under ISO 22716 (Cosmetic GMP) with documented batch-level cleaning between products. Dedicated powder-handling and packaging equipment, restricted personnel access, and validated cleaning verification.
Related Materials & Sister Sites
- HJSIL® Fumed Silica — flame-hydrolysis route, non-porous, industrial chemistry.
- MEGEL® Silica Aerogel — porous nanostructured silica, thermal insulation.
- HMMAT® Matting Agents — wood / paint matting silica; some grades FDA-compliant for food packaging.
- MESIL® Specialty Fumed Silica — high-purity grade for cosmetic / optical / LED applications.
- Silicone Oils — carrier / emollient for cosmetic formulations.
- For silicone curing catalysts and organotin-free alternatives, see chemzip.com. For dental and cosmetic-grade titanium dioxide (opacifier pigment), see coatingsink.com/products/titanium-dioxide/. For silicon-chemistry primers and pharmacopoeia background, see silicon-materials.com.
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