Calcium Stearate

Calcium Stearate prevents ingredients from clumping together and from sticking to the tablet punches or capsule filling machine. Lubricants also ensure that tablet formation and ejection can occur with low friction between the solid and die wall. Common minerals like talc or silica, and fats, e.g. magnesium stearate or stearic acid are the most frequently used lubricants in tablets or hard gelatin capsules.
There are three roles identified with lubricants as follows:
1. True Lubricant Role:
• To decrease friction at the interface between a tablet's surface and the die wall during ejection and reduce wear on punches & dies.
2. Anti-adherent Role:
• Prevent sticking to punch faces or in the case of encapsulation, lubricants
• Prevent sticking to machine dosators, tamping pins, etc.
3. Glidant Role:
• Enhance product flow by reducing interparticulate friction.

There are two major types of lubricants:
1. Hydrophilic
• Generally poor lubricants, no glidant or anti-adherent properties.
2. Hydrophobic
Most widely used lubricants in use today are of the hydrophobic category. Hydrophobic lubricants are generally good lubricants and are usually effective at relatively low concentrations. Many also have both anti- adherent and glidant properties. For these reasons, hydrophobic lubricants are used much more frequently than hydrophilic compounds. Examples include magnesium stearate.

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