Strength of the Compacts from Avicel PH 102 and Avicel PH 301 and the Influence on it Exerted by Magnesium Stearate The paper evaluated the strength of compacts made of microcrystalline cellulose of two types used as dry binders in the technology of direct compression of tablets, i.e. Avicel PH 102 and Avicel PH 301. The effect of three concentrations of the lubricant magnesium stearate (0.4; 0.8; 1.2 %) on the strength of tablets made from these substances was also evaluated. Tables were compressed using three forces of compression (3; 3.5, and 4 kN). On the basis of the obtained results it can be concluded that Avicel PH 102 provides, under identical forces of compression, stronger compacts than Avicel PH 301 does. It has been further found that a magnesium stearate concentration of 0.4 markedly decreases the tensile strength of Avicel PH 102 tablets, and another marked decrease is observed with a concentration of 1.2 %. The decrease in the tensile strength of Avicel PH 301 compacts due to magnesium stearate is not so marked as in Avicel PH 102 tablets, and with stearate concentrations of 0.4 % and 1.2 % the difference in strength is not of such importance in comparison with the previous concentrations.

        Key words: Avicel PH 102 – Avicel PH 301 – magnesium stearate – tensile strength of tablets