The present paper evaluated the tensile strength of tablets made from the dry binder Prosoly SMCC 90 and the influence of three concentrations of the lubricant magnesium stearate on the tensile strength of tablets manufactured from this material. The results were compared with the same evaluation in Avicel PH 102. The tested concentrations of the stearate were 0.4, 0.8 and 1.2 %. The tablets were compressed by three press powers (3, 3.5, and 4 kN). On the basis of obtained results it can be stated tkat under the same press powers Prosoly SMCC 90 alone yields stronger compacts than Avicel PH 102. From the viewpoint of decreased strength of compacts by adding magnesium stearate, the dry binder Prosoly SMCC 90 is much less sensitive than Avicel PH 102. In Avicel PH 102 a marked decrease in tensile strength was recorded with an addition of 0.4 %, which was not observed with Prosoly SMCC 90. A more significant decrease in the strength of compacts was shown by the substance not until a stearate concentration of 0.8 %. The highest employed stearate concentration of 1.2 % decreases the tensile strength of tablets made from Prosoly SMCC 90 in the press powers of 3.5 and 4 kN two times less than the tensile strength of the compacts from Avicel PH 102.

        Key words: Prosoly SMCC 90 -Avicel PH 102 - magnesium stearate -tensile strength of tablets