Mechanism of the formation of hollow spherical granules using a high shear granulator

Analysis of Over-Granulated Particles using Near-Infrared Chemical Imaging and Attenuated Total Reflectance-Infrared Techniques

To elucidate the previously described mechanism of segregation caused by over-granulation, we analyzed over-granulated particles using the techniques of near-infrared chemical imaging (NIR-CI) and attenuated total reflectance infrared (ATR-IR). The same area of over-granulated particles was measured using both techniques. The distributions of the active ingredient, ethenzamide, and other additives in the over-granulated particles were compared. As ATR-IR chemical imaging easily identifies components and has higher spatial resolution than NIR-CI, it permitted a clearer observation of the distribution of ingredients, particularly in fine cornstarch particles. Using both techniques, segregation of components were observed as previously reported. Although lactose was barely observed in the ethenzamide-enriched regions, ethenzamide and cornstarch were observed in lactose-enriched regions. This suggests that only lactose aggregated and segregated from the other compounds during the process of granulation. Hydrophilic lactose aggregation is supposedly caused by the behavior of water during granulation. In conclusion, ATR-IR chemical imaging is an excellent analytical technique for obtaining the detailed distribution of components. Furthermore, fusion of ATR-IR chemical imaging and NIR-CI is a useful tool for understanding drug manufacturing processes and may be applicable to pharmaceutical manufacturing and quality control.

Improved Understanding of the High Shear Wet Granulation Process under the Paradigm of Quality by Design Using Salvia miltiorrhiza Granules

BACKGROUND

High shear wet granulation (HSWG) is a shaping process for granulation that has been enhanced for application in the pharmaceutical industry. However, study of HSWG is complex and challenging due to the relatively poor understanding of HSWG, especially for sticky powder-like herbal extracts.

AIM

In this study, we used Salvia miltiorrhiza granules to investigate the HSWG process across different scales using quality by design (QbD) approaches.

METHODS

A Plackett-Burman experimental design was used to screen nine granulation factors in the HSWG process. Moreover, a quadratic polynomial regression model was established based on a Box-Behnken experimental design to optimize the granulation factors. In addition, the scale-up of HSWG was implemented based on a nucleation regime map approach.

RESULTS

According to the Plackett-Burman experimental design, it was found that three granulation factors, including salvia ratio, binder amount, and chopper speed, significantly affected the granule size (D50) of S. miltiorrhiza in HSWG. Furthermore, the results of the Box-Behnken experimental design and validation experiment showed that the model successfully captured the quadratic polynomial relationship between granule size and the two granulation factors of salvia ratio and binder amount. At the same experiment points, granules at all scales had similar size distribution, surface morphology, and flow properties.

CONCLUSIONS

These results demonstrated that rational design, screening, optimization, and scale-up of HSWG are feasible using QbD approaches. This study provides a better understanding of HSWG process under the paradigm of QbD using S. miltiorrhiza granules.