Colloidal Silicon Dioxide — Pharmaceutical Grade (Ph.Eur. / USP-NF)
Pharmaceutical-grade colloidal silicon dioxide (colloidal anhydrous silica) is a high-purity amorphous fumed SiO2 manufactured to comply with the monographs of the European Pharmacopoeia (Ph.Eur. 8.0 "Silica, Colloidal Anhydrous"), United States Pharmacopeia/National Formulary (USP-NF), and Japanese Pharmacopoeia (JP). It is used in solid oral dosage form manufacturing as a glidant (0.1–0.5%), tablet lubricant, and suspending agent, and in topical and semi-solid preparations as a thickener and stabilizer.
Technical Specifications
| Properties and Test Methods | Unit | Typical Value | Standardization |
|---|---|---|---|
| Specific surface area (BET) | m²/g | 200 ± 25 | Ph.Eur. / GB/T 10722 |
| pH value (in 4% dispersion) | – | 3.5 ~ 4.5 | Ph.Eur. |
| Loss on drying (2h @ 105°C) | Wt% | ≤ 2.5 | Ph.Eur. |
| Loss on ignition (2h @ 1000°C) | Wt% | ≤ 5.0 | Ph.Eur. |
| SiO2 content (ignited material) | Wt% | ≥ 99.0 | Ph.Eur. |
| Heavy metals (as Pb) | ppm | ≤ 25 | Ph.Eur. 2.4.8 |
| Chlorides | ppm | ≤ 250 | Ph.Eur. |
| Sulfates | ppm | ≤ 500 | Ph.Eur. |
| Arsenic | ppm | ≤ 2 | Ph.Eur. |
| Tamped density | g/L | 40 ~ 60 | USP |
Pharmacopeial Compliance: Ph.Eur. 8.0 (Silica, Colloidal Anhydrous), USP–NF (Silicon Dioxide, Colloidal), JP XVII
Application Suggestions
Tablet Glidant and Anti-Adherent
The most common pharmaceutical application — added at 0.1–0.5% w/w to tablet blends to improve powder flow to the punch die and reduce sticking to tooling surfaces. Colloidal silicon dioxide is particularly effective for cohesive active pharmaceutical ingredients (APIs) and hygroscopic excipients that resist flow on high-speed tablet presses.
Suspension Stabilizer in Liquid Dosage Forms
Creates a stable thixotropic network in oral suspensions, topical gels, and nasal spray formulations. The colloidal silica particles form a three-dimensional gel structure at rest that breaks under shear (pouring or shaking), enabling resuspension and homogeneous dosing.
Dry Powder Inhaler (DPI) Carrier
Used as an aerosolization aid in dry powder inhaler formulations, improving drug-carrier detachment during inhalation. The ultra-fine surface coverage reduces cohesive forces between API particles and lactose carrier, improving fine particle fraction (FPF) and delivered dose consistency.
Semi-Solid and Topical Formulations
Functions as a gelling and thickening agent in hydrophilic gels, creams, and ointments. At 2–5% loading, it provides a clear, stable gel structure for topical drug delivery systems and cosmeceutical preparations.
Technical Support & FAQ: Colloidal Silicon Dioxide Pharma Grade
+Q1: What are the key features and applications?
Pharma-Grade Colloidal Silicon Dioxide meets global pharmacopeial standards:
- Core Functions: Tablet glidant, suspension stabilizer, DPI aerosolization aid, topical thickener
- Key Features: Full Ph.Eur./USP/NF compliance; lot-specific CoA with pharmacopeial test results; GMP manufacturing
- Primary Applications: Solid oral dosage forms (tablets, capsules), oral suspensions, DPI, topical gels
+Q2: How does pharma-grade colloidal SiO2 differ from food-grade?
| Parameter | Food-Grade (E551) | Pharma-Grade (Ph.Eur./USP) |
|---|---|---|
| Heavy metals (Pb) | ≤10 ppm | ≤25 ppm (Ph.Eur. limit, stricter test method) |
| Chlorides | Not specified | ≤250 ppm |
| Sulfates | Not specified | ≤500 ppm |
| CoA content | Food additive cert | Full pharmacopeial test report |
| GMP documentation | Not required | Required (batch record, DMF available) |
+Q3: What regulatory documentation is available?
- Drug Master File (DMF): Available for submission to FDA (USA) and equivalent regulatory agencies
- Batch CoA: Full pharmacopeial test results per Ph.Eur./USP-NF/JP
- CEP (Certificate of Suitability): Available on request for EU submissions
- GMP Certificate: Manufacturing site GMP certificate for regulatory submissions
+Q4: What are the typical lead times and payment terms?
- Lead Time: Typically 10–21 days (pharma-grade requires additional QC release testing)
- Payment Terms: T/T, L/C at sight, and D/P
- Sample Support: Free samples (200g–1kg) with full pharmacopeial CoA for formulation development
Packing & Storage Information
Storage Conditions
Store in tightly closed containers in a dry, clean area at controlled room temperature (15–25°C). Protect from moisture, strong acids, and bases. Keep away from incompatible materials. Use within 3 years of manufacture date. Retest if storage period is exceeded.