Impact of number of compression cycles and rotary table speed on tablets strength and friability

The aim of the research is to determine the impact of the number of compression cycles and rotary table speed on the strength and friability of tablets.It were investigated two tablet samples manufactured on an industrial rotary press with rotary table speed 30-80 rpm.Tablet strength was assessed by destructive stress in the diametrical direction, and friability was measured by the percentage of mass lost during processing in a rotating drum.When the rotary table speed is increased from 30 to 80 rpm, tablet strength is decreased to 10%.The most significant reduction in strength was observed at the rotary table speed of 60-80 rpm.Friability in this range is increased intensively from 0.2% to 1.2%, exceeding both pharmacopoeial (1%) and recommended (0.5%) standards.After 300,000 compression cycles, tablets lost to 8% of their strength.The decrease in tablet quality is attributed to product sticking to the press tool surface, increased surface roughness, friction coefficient, and adhesive strength.Consequently, the tablet's outer layer exhibits lower strength properties and is prone to rapid deterioration.The reduced strength at higher rotary table speed is explained by decreased dwell time in the die and higher ejection speed, which lowers the strength of its outer layers.Increased tablet friability affects subsequent manufacturing operations: dust accumulates in the tablet feed channels for blister packaging, hindering their movement, and the tablets lose mass during coating application in drum-type machines, among others.Decreased tablet strength leads to its fragmentation during various technological operations and storage.For the tablets used in the study on the Korsch XL 400 tablet press, the optimal rotor rotation frequency was determined to be 50 rpm.Increasing the rotation frequency, and thus productivity, is achievable through more frequent polishing of die and punch surfaces.