Tablet Press Woes

Initial Situation An experimental granulation technique is to be evaluated a sample of tablets of the hrst trial run is sent to the analytical laboratory for the standard batch analysis prescribed for this kind of product, including content uniformity (homogeneity of the drug substance on a tablet-to-tablet basis, see USP Section (905) ), tablet dissolution, friability (abrassion resistance), hardness, and weight. The last two tests require little time and were therefore done first. (Note Hardness data is either given in [kg-force] or [N], with 1 kg = 9.81 Newton). 

Conclusion The hardness results are very variable (CV 17%), while the weight scatters only about 2%, so a request for more tablets is issued  

Conclusion No improvement, something is wrong with either the product or the analytical procedure measuring hardness and weighing are such simple procedures, however, that it is hard to place the blame on the very reliable laboratory technician. 

Strategy Since the tablet press is still in operation, an experiment is devised 

Results The hardness and the weight are measured (for 10 tablets from each of the 12 stamps, see HARDNESS.dat, use programs XYZ, XYZCELL, LINREG) and are graphed (Fig. 4.11, left). 

---