Magnesium stearate is often used as an anti-adherentin the manufacture of medical tablets, capsules, and powders. In this regard, the substance is also useful because it has lubricating properties, preventing ingredients from sticking to manufacturing equipment during the compression of chemical powders into solid tablets; magnesium stearate is the most used lubricant for tablets. However, it might cause lower wettability and slower disintegration of the tablets and slower and even lower dissolution of the drug.

Magnesium stearate can also be used efficiently in dry coating processes. In the creation of pressed candies, magnesium stearate acts as a release agent and it is used to bind sugar in hard candies such as mints.

Magnesium stearate is a common ingredient in baby formulas.


Product Magnesium Stearate 
Description Complies A Very Fine, Light, White Powder, Odorless or with a faint odor of stearic acid; unctuous and free from grittiness
Solubility Complies Practically insoluble in water, in ethanol & in ether
(A) Freezing Point                     56O C Not Less Than 53O C
(B)Acid Value Complies The Acid Value of the fatty acid is 195 to 210
(C)Fatty Acid Composition Complies As Per IP
(D)Reaction on Magnesium  Complies Solution A gives the reaction of magnesium 
Appearance of solution Complies Solution A is not more intensely colored than reference solution YS6
Appearance of solution of the fatty acids. Complies The solution is clear, and not more intensely colored than reference solution YS5
Acidity of Alkalinity  0.004 ml of 0.1 M HCI is Required NMT 0.05 ml of 0.1M HCI or 0.1 M NaOH is required to change the color of the solution
Acid value of the fatty acids 208.2 195 to 210
Free Stearic acid 1.41% NMT 3 %
Zinc Stearate  Complies No violet Precipitate is formed 
Heavy Metals Complies Max 20 ppm
Chlorides Complies Max 250 ppm
Sulphates Complies Max 0.6%
Loss on Drying at 105OC,1.0 g 2.86% NMT 6.0%
Bulk Density (In House) 0.22 g/cc 0.15-0.3 g/cc
Assay 4.75% 3.8% -5.0% Mg on the Dried Basis
The Fatty acid Fraction Stearic Acid Complies NLT 40.0%
Sum of stearic acid and palmitic acid Complies NLT 90.0%
TAMC <1000 cfu/g Acceptance criterion 103 cfu/g
TYMC <100 cfu/g Acceptance criterion 102 cfu/g
Escherichia coli Absent Absent
Salmonella Absent Absent