Stearic acid is a waxy oil fraction that acts as a lubricant to fill capsules when a dry powdered ingredient (or ingredient mix) is uncooperative, based on issues involving density, stickiness, flowability under pressure, etc. It is also used as an ingredient that helps tablets hold together and break apart properly.

Appearance                       blocks, flakes, powder or granular
Color, Hazen                       =100
Acid Value,                      mhKOH/g205-210
Saponification Value, mg KOH/g        206-211
Iodine    Value, g               I2/100g=0.5
Moisture, %                    =0.2
Freezing Point,                °C54-57
Inorganic Acid,                     %=0.001