Magnesium Stearate
The magnesium salt of stearic acid supplied by Chelora Chemicals — the standard tablet and capsule lubricant used to reduce friction in virtually every solid oral dosage form manufactured — exported from Indonesia in bags with full batch documentation on every shipment.
What Magnesium Stearate is, and why buyers source it
A working overview of the compound's chemistry, its role as the standard lubricant across solid-dose manufacture, and the grade Chelora Chemicals keeps in regular supply.
Magnesium Stearate is the magnesium salt of stearic acid, a long-chain fatty acid. Its structure — a small, polar magnesium centre flanked by two long, non-polar hydrocarbon tails — gives it a soap-like, highly lubricating character: the hydrocarbon tails readily coat powder particle and equipment surfaces with a thin, slippery film, dramatically reducing friction between particles and between the powder bed and tooling surfaces.
It is a fine, white, very low-density, bulky, odourless powder with a slightly greasy feel, practically insoluble in water and most common solvents, which is consistent with its role as a surface-coating lubricant rather than a dissolved functional ingredient. It is chemically and physically stable under normal pharmaceutical storage conditions.
Where it fits in the formulation chain
Magnesium Stearate's primary and almost universal use is as a lubricant in tablet and capsule manufacture, added at very low levels (typically 0.25–1% w/w) in the final blending step before compression or capsule filling, where it reduces friction between the powder blend and the punches, dies and capsule-filling equipment, preventing sticking and ensuring smooth, consistent production. It is one of the most widely used excipients in the entire pharmaceutical industry.
Grade we supply
Chelora Chemicals offers Magnesium Stearate compliant with USP/EP/JP monographs, available in vegetable-source grade, suitable for tablet and capsule lubricant applications, supplied with a batch-wise certificate of analysis.
How Magnesium Stearate is made
An overview of the production route for orientation purposes. Our manufacturing partners' own process parameters and in-process controls are proprietary and are not disclosed beyond what is needed to interpret the certificate of analysis.
Magnesium Stearate is manufactured by reacting stearic acid (or a stearic/palmitic acid blend derived from vegetable or animal fat) with a magnesium source, typically magnesium hydroxide or magnesium oxide, in an aqueous or solvent medium: 2 C₁₈H₃₆O₂ + Mg(OH)₂ → Mg(C₁₈H₃₅O₂)₂ + 2 H₂O. The resulting precipitate is filtered, dried and milled to the required fine particle-size grade.
Why direct precipitation from stearic acid is the standard process
Reacting stearic acid directly with a magnesium base gives a simple, well-understood precipitation reaction that yields the fine, bulky powder structure the pharmaceutical industry relies on for lubrication, which is why it has been the standard production method since magnesium stearate was first adopted as a tableting excipient.
Industries and processes that use it
Magnesium Stearate is consumed across virtually all solid oral dosage-form manufacture, where its lubricating, anti-adherent function is the main draw. The fields below account for most of the demand we see through our export desk.
Tablet Lubrication
Blended into the final powder or granule mix before compression to reduce friction between the blend and the tablet press punches and dies, preventing sticking and capping.
Capsule Filling Lubrication
Used to reduce friction in powder and granule blends during hard-capsule filling, ensuring smooth, consistent fill weights on high-speed encapsulation equipment.
Anti-Adherent for Tooling
Prevents powder from sticking to punch faces and die walls during compression, a critical function for maintaining tablet appearance and press efficiency.
Cosmetic & Personal-Care Formulation
Used in powder cosmetics and some personal-care formulations for its lubricating, anti-caking and water-repellent properties.
How the molecule is typically carried forward
The soap-like structure, with a small polar head and two long non-polar tails, governs almost all of this material's functional behaviour as a lubricant. The mechanisms below account for most of how Magnesium Stearate performs its lubricating role.
Acid-Base Precipitation (Upstream)
Stearic acid reacts with a magnesium base to precipitate magnesium stearate, the fine, bulky powder used as a pharmaceutical lubricant.
Particle-Surface Coating
During blending, magnesium stearate particles shear and spread across the surfaces of the other blend components, forming a thin, hydrophobic lubricating film.
Friction Reduction at the Tooling Interface
The lubricating film reduces friction between the powder blend and the punch and die surfaces during compression, easing tablet ejection and preventing sticking.
Hydrophobic Surface Effect (Overblending Risk)
Excessive blending time or lubricant level can over-coat granule surfaces, slowing water penetration and potentially delaying tablet disintegration and dissolution — a key formulation-development consideration.
Magnesium Stearate against other amines we supply
Buyers sourcing Magnesium Stearate for tablet or capsule lubrication often need a related tableting excipient. A quick reference to what else is on our regular supply list.
| Product | CAS Number | Category | Notes |
|---|---|---|---|
| Magnesium Stearate | 557-04-0 | Fatty-acid magnesium salt lubricant | The product on this page — the standard tablet and capsule lubricant. |
| Microcrystalline Cellulose | 9004-34-6 | Purified crystalline cellulose | The standard diluent lubricated with magnesium stearate in most tablet formulations — see its product page. |
| Croscarmellose Sodium | 74811-65-7 | Cellulose-based superdisintegrant | A related tablet excipient commonly formulated alongside magnesium stearate — see its product page. |
| Lactose Monohydrate | 64044-51-5 | Sugar diluent | The most widely used tablet diluent, typically lubricated with magnesium stearate — see its product page. |
Exact physical constants and purity specifications are confirmed per batch on the certificate of analysis — treat the notes above as a sourcing guide, not a specification sheet, for products other than Magnesium Stearate.
Safety classification at a glance
Based on GHS classification as commonly listed for this substance. This is a summary for orientation only — always work from the current safety data sheet supplied with your specific batch.
Not classified as hazardous under GHS; a long-established, widely used pharmaceutical excipient.
Fine, bulky powder may cause transient mechanical irritation to eyes or respiratory tract; handle with standard dust control.
No significant acute toxicity hazard under normal pharmaceutical handling.
Fine organic powders can present a combustible-dust hazard in sufficient airborne concentration; manage per standard dust-handling practice.
Standard dust mask and gloves are sufficient for routine handling in a pharmaceutical manufacturing environment.
Keep dry and sealed; avoid excessive compaction during storage given its very low bulk density.
Follow standard pharmaceutical good manufacturing practice (GMP) for handling and cross-contamination control.
Not Classified — no GHS hazard pictogram applies to this excipient.
This material is not classified as hazardous under GHS and presents no significant acute toxicity hazard under normal pharmaceutical handling, though fine, bulky powder may cause transient mechanical irritation to eyes or the respiratory tract and, like other fine organic powders, can present a combustible-dust hazard in sufficient airborne concentration. It should be handled with standard dust control and good industrial hygiene. Full handling and storage guidance is in the MSDS issued with every shipment, and standard pharmaceutical GMP practice should be followed.
Keeping it on spec between delivery and use
General storage guidance for this grade. Site-specific storage rules, segregation requirements and re-test intervals should follow your own EHS procedures and the MSDS issued with your batch.
Store in a cool, dry area in tightly sealed original packaging, away from moisture and strong oxidizing agents, avoiding excessive compaction given its very low bulk density. As a chemically stable, non-hygroscopic powder it is comparatively straightforward to store under standard pharmaceutical warehousing conditions. If a batch is held past its retest date, re-check magnesium content and particle size before use.
How it ships from Indonesia
Standard packing and export terms for this product. Confirm exact figures against your order — they vary slightly by destination and quantity.
What travels with every batch
Specification is agreed before the purchase order, not discovered on arrival. Every shipment of Magnesium Stearate leaves with a documented, checkable paper trail.
Certificate of Analysis
Batch-wise assay (by titration/GC), colour and relevant physical constants, issued against the agreed specification so your QC team can check it, not just file it.
Safety Data Sheet
GHS-format SDS in English covering hazard classification, handling, storage, first-aid and spill response for the exact grade of Magnesium Stearate shipped.
Technical Data Sheet
Reference physical and chemical properties, recommended storage and typical applications, for internal circulation to your process or R&D teams.
Certificate of Origin
Confirms Indonesian origin for customs clearance and any preferential-duty claim at your destination port.
Dangerous Goods Declaration
UN packing group, classification and shipper's declaration prepared ahead of loading so documentation never holds up customs.
Third-Party Inspection
Independent pre-shipment inspection and re-sampling can be arranged on request, at your cost, for buyers who require it as a matter of policy.
Frequently asked questions
What buyers most often ask our sales desk about this grade.
01What is Magnesium Stearate used for?+
02What is the CAS number of Magnesium Stearate?+
03How is Magnesium Stearate made?+
04What grade does Chelora Chemicals supply?+
05Why is only a very small amount of Magnesium Stearate needed?+
06Is Magnesium Stearate hazardous?+
07What packing options are available?+
08How long does delivery take?+
09Can I get a sample before placing a bulk order?+
10Do you supply Microcrystalline Cellulose and Lactose Monohydrate as well?+
Need Magnesium Stearate on spec, on time?
Send us your required purity, quantity, packing preference and destination port. Our desk quotes most enquiries within one working day.