Introduction to Magnesium Stearate as a pharmaceutical excipient
Magnesium Stearate a pharmaceutical exicpient
Magnesium stearate, also known as magnesium octadecanoate, is a common additive used in the pharmaceutical industry. It is a white, odorless, and tasteless powder that is highly insoluble in water, but soluble in organic solvents. The chemical formula for magnesium stearate is Mg(C18H35O2)2.
Chemical structure of magnesium stearate. Magnesium stearate, also known as octadecanoic acid, exists as a salt containing two stearate anions and a magnesium cation.
Manufacturing of Magnesium Stearate
Magnesium stearate can be derived from various sources such as animal, vegetable, and synthetic materials. Animal-derived magnesium stearate is usually sourced from beef or pork tallow, while vegetable-derived magnesium stearate is obtained from hydrogenated cottonseed or palm oil. Synthetic magnesium stearate is produced by combining magnesium oxide or magnesium hydroxide with stearic acid.
Differences between animal, vegetable, and synthetic magnesium stearate
Animal-derived magnesium stearate may be considered controversial by some people because of its source. Additionally, it may have a higher risk of contamination with impurities such as heavy metals, which may have adverse effects on human health. Vegetable-derived magnesium stearate is a more widely accepted source and is generally regarded as safe. Synthetic magnesium stearate, on the other hand, is considered to be the purest form of magnesium stearate, with the least likelihood of impurities.
Magnesium Stearate as pharmaceutical excipient – See our introduction video
USP-NF and EP Monographs for Magnesium Stearate
The United States Pharmacopeia-National Formulary (USP-NF) and European Pharmacopoeia (EP) both have monographs for magnesium stearate. The USP-NF monograph for magnesium stearate specifies that it must contain not less than 4.0% and not more than 5.5% of magnesium (Mg) and not less than 40.0% and not more than 60.0% of stearic acid (C18H36O2). It must also pass certain tests for identification, assay, and heavy metals content.
EP monograph
The EP monograph for magnesium stearate specifies that it must contain not less than 4.0% and not more than 5.5% of magnesium (Mg) and not less than 40.0% and not more than 60.0% of stearic acid (C18H36O2). It must also pass certain tests for identification, assay, and impurities such as lead, cadmium, and arsenic.
CAS Number: 557-04-0
Uses of magnesium stearate as excipient in pharmaceuticals
Magnesium stearate is a widely used excipient in the pharmaceutical industry, serving a variety of purposes in drug formulation and manufacturing. Here are some of the major uses of magnesium stearate in pharmaceutical products:
- Lubricant: One of the most common uses of magnesium stearate in pharmaceutical products is as a lubricant. It is added to drug formulations to reduce friction between particles and facilitate their movement through manufacturing equipment, such as tablet presses and capsule filling machines. This helps to ensure consistent and efficient production of drug products. Magnesium stearate is used as a lubricant for tablets and capsules in a range of 0.2 to 5%.
- Anti-adherent: Magnesium stearate can also serve as an anti-adherent in pharmaceutical products. It is added to prevent drug particles from sticking to the surfaces of manufacturing equipment, which can cause blockages or uneven dosing.
- Flow agent: In addition to lubrication, magnesium stearate can also improve the flow properties of drug powders. It is added to reduce the cohesive forces between particles and improve their flowability, making it easier to handle and process them during manufacturing.
General Applications in Oral Dosage for Pharmaceuticals and/or Nutraceuticals
- Blends, Granules, Pellets Premix
- Chewable tablets
- Effervescent tablets
- Hard capsules
- Lozenge
- Orally Dispersible tablet
- Swallowable tablet
Overall, magnesium stearate is an important ingredient in many pharmaceutical products, helping to ensure consistent quality, efficient manufacturing, and effective drug delivery.
Magnesium Stearate Excipients on pharmaexcipients.com
| Product | Company |
|---|---|
| LUBRI-PREZ™ 4 | JRS Pharma |
| LUBRI-PREZ™ 2 | JRS Pharma |
| Parteck® LUB MST (Magnesium Stearate Vegetable Grade) | Merck KGaA |
| Magnesium Stearate – LS | Roquette |
| Magnesium Stearate – HS | Roquette |
| Magnesium Stearate | Roquette |
| Magnesium Stearate | Dr. Paul Lohmann |