Compression Properties of Cephalexin Powder and Physical Properties of the Tablet

Abstract

The compression process of cephalexin (CEX) powder was studied by using a tabletting machine with punches of 0.7, 1.0 and 2.0 cm diameter, and the maximum compression stress (MP), the compression loss energy (LE), the elastic energy (EE), the compression energy (CE), the hardness of the tablet (H) and the elastic recovery (R) were measured. The compression process followed Bal'shin's equation, and was independent of sample weight in the range of 110 to 300 mg. In the compression process with the 0.7 cm punch the plot of the compression stress versus the thickness of the powder bed was shifted to the slightly higher pressure side as compared with the plots for the 1.0 and 2.0 cm punches, presumably because the die wall friction of the 0.7 cm punch was larger than that of the 1.0 and 2.0 cm punches. Elastic behavior appeared on high-pressure compression of CEX powder. The Young's modulus obtained from the relation between MP and R was calculated to be 4.75×10⁹ dyn/cm². The tensile strength (TS) and R value increased with increasing value of MP.