Formulation and development of tablets based on Ludipress and scale-up from laboratory to production scale

In spite of the wealth of experience available in the pharmaceutical indust ry, tablet formulations are still largely developed on an empirical basis, and the scale-up from laboratory to production is a time-consuming and cost ly process. Using Ludipress(R) greatly simplifies formulation development a nd the manufacturing process because only the active ingredient Ludipress a nd a lubricant need to be mixed briefly before being compressed into tablet s. The studies described here were designed to investigate the scale-up of Ludipress-based formulations from laboratory to production scale, and to pr edict changes in tablet properties due to changes informat, compaction pres sure, and the use of different tablet presses. It was found that the tensil e strength of tablets made of Ludipress increased linearly with compaction pressures rip to 300 MPa. It was also independent of the geometry of the ta blets (diameter, thickness, shape). It is therefore possible to give an equ ation with which the compaction pressure required to achieve a given hardne ss can be calculated for a given tablet form. The equation has to be modifi ed slightly to convert from a single-punch press to a rotary tableting mach ine. Tablets produced in the rotary machine at the same pressure have a sli ghtly higher tensile strength. The rate of increase in pressure, and theref ore the throughput, has no effect on the tensile strength of Ludipress tabl ets. It is thought that a certain minimum dwell time is responsible for thi s difference. The production of tablets based on Ludipress can be scaled up from one rotary press to another without problem if the powder mixtures ar e prepared with the same mixing energy. The tensile strength curve determin ed for tablets made with Ludipress alone can also be applied to tablets wit h a small quantity (<10%) of an active ingredient.