Issue link: https://www.e-digitaleditions.com/i/922724
36 January 2018 Tablets & Capsules Figure 2 PSD of granules by laser diffraction Distribution density (q 3 ) Particle size (μm) 2.5 2 1.5 1 0.5 0 1 501 1001 1501 2001 HPC-SSL HPC-SL HPC-L Figure 3 Compression force versus breaking force in fluid-bed granulation Breaking force (N) Compression force (kN) 300 250 200 150 100 50 0 5 10 15 20 25 30 HPC-SSL HPC-SL HPC-L Tablet disintegration. The disinteg- ration of the tablets also showed a dependence on the HPC MW. It is well known that a high viscosity inside the tablet matrix can prolong disintegration by reducing water uptake. Figure 4 shows the disintegration time of tablets with a breaking force of 200 newtons. As expected, tablets made using the lowest-viscosity (lowest-MW) HPC (SSL) disintegrated fastest, followed by SL and L. Tablet friability. All the tablets showed acceptable friability results (Figure 5). No impact of the HPC MW was observed. Binder solution concentration. Though this study did not examine the effects of binder concentration, it is expected that the low MW of HPC- S S L w o u l d a l l o w a h i g h e r concentration of polymer in the binder solution while maintaining an acceptable viscosity. In industry practice, it is typical for binder solutions to be prepared to a viscosity of approximately 200 to 500 mPa·s. If the binder solution's viscosity were fixed at 200 mPa·s, the corresponding polymer concentrations would be roughly 20 percent for SSL, 11 percent for SL, 8 percent for L. The higher solids content of an SSL binder solution would allow faster batch times and require less drying energy. For example, if a batch required a spraying time of 120 minutes with an 8 percent solution of HPC-L, the same batch could be completed in 48 minutes using a 20 percent solution of HPC-SSL. Correspondingly, the energy required would decrease by more than half, batch time would shorten, and water usage would decrease. Conclusions: Fluid-bed granulation. In this study: The largest granules were produced when the highest-MW binder (HPC-L) was used. Granule size increased as the HPC's MW increased: SSL < SL < L. T h e n a r r o w e s t P S D o f t h e obtained granules was achieved using the lowest-MW binder (HPC-SSL). The compaction properties of granules that included the lowest-MW binder (HPC-SSL) were best when compressed at high compression forces (>15 kN). Figure 4 Disintegration time of tablets with breaking force of 200 N Disintegration time (min) 50 45 40 35 30 25 20 15 10 5 0 HPC-SSL HPC-SL HPC-L