By their nature, sliding agents can be divided into two groups: fats and fat-like substances – paraffin, hydrogenated vegetable fats and cocoa butter, added in amounts up to 2%; calcium and magnesium stearates, pure stearic acid (< 1%); powdered substances – talc, starch and thein-80. Talc is added to the granulate no more than 3%, as it acts irritatingly on mucous membranes. Powdered substances are used more than fatty substances, because the latter affect the solubility and chemical stability of tablets. Powdered slip agents are introduced by powdering the granulate. Sliding agents have another function: to remove the electrostatic charge from the powder or phanulate particles, which also improves their flowability. Talc, stearates, aerosil are used for this purpose.

Talc is one of the substances representing a type of lamellar silicates, which are based on layers of the densest hexagonal packing. The layers are bound together by residual van der Waals forces (the weakest of all chemical bonds). Due to this property and high dispersibility of particles they are capable of deformation and good sliding. It is advisable to introduce these substances into the composition of tabletting masses in a highly dispersed state. The greater the degree of refinement, the greater the surface area of the tabletting mass they can cover for the same amount. Since talc and stearates are hydrophobic sliding substances, they impede the penetration of digestive liquids into the porous structure of the tablet, which worsens its disintegration.