Dicalcium Phosphate Blended with Native or Agglomerated Tapioca Starch for the Production of Directly Compressed Tablets

The objective of this work was to investigate the characteristics of powders and tablets prepared from blends of dicalcium phosphate dihydrate (DCPD) with native tapioca starch (TS) or agglomerated tapioca starch (AGTS) at various ratios. The results showed that DCPD had a Carr’s index of 4.92%, whereas AGTS and TS were 14.70% and 27.45%, respectively. Moreover, the repose angle of TS (39.04°) was higher than that of DCPD (32.17°) and AGTS (32.40°), resulting in reduced blend flowability as TS content increased. Higher TS or AGTS ratios in the blends resulted in decreased yield pressure and increased yield strength compared with DCPD, as indicated by the Heckel and Kawakita plots, thereby enhancing plastic deformation under compression. TS tablets were harder than DCPD tablets at 62.4 and 124.9 MPa. However, the trend reversed at higher pressures. In contrast, the hardness of AGTS tablets was consistently higher than that of DCPD tablets. Additionally, the DCPD-AGTS blends produced propranolol hydrochloride (PPN) tablets with higher hardness than the DCPD-TS blends. The DCPD tablets with PPN showed the longest disintegration time (>45 min), whereas those of the TS and AGTS tablets with PPN had disintegration times of 1.09 and 6.22 min, respectively. Thus, the addition of TS or AGTS improved the tablet disintegration. Moreover, the PPN dissolution from the DCPD tablets was enhanced by the incorporation of TS or AGTS, particularly at the 0.5:0.5 DCPD:TS/AGTS ratio. Overall, AGTS can modify the properties of DCPD tablets compared to TS. The DCPD-AGTS blends show promising performance for producing immediate-release tablets.