Purpose: To examine the original flowability, compressibility and compactibility of Saraca indica bark powder and its tablet formulations.

Methods: Saraca indica bark powder was subjected to various quantitative tests including acid insoluble ash, total ash, foreign organic matter, alcohol soluble extractive and water soluble extractive. Its flowability and compressibility were determined using Kawakita, Heckel and Leuenberger relationships. Tablets were prepared from the powder by direct compression and wet granulation techniques and characterized.

Results: Kawakita analysis revealed lower cohesiveness of granules (3.877 ± 0.890) compared to the powder (6.176 ± 1.030), and hence improved flowability. From Heckel analysis, the higher value of intercept (A) for granules (4.38 ± 0.45) implies higher degree of fragmentation than direct compression DC formulation (2.90 ± 0.33) and powders (2.44 ± 0.12). The compression susceptibility parameter obtained from Leuenberger equation for compacts formed by wet granulation technique (0.183 ± 0.045 1/kg/cm²) indicate that maximum crushing strength is reached faster at lower pressures of compression than for Saraca indica bark powder (0.073 ± 0.025 1/kg/cm²) and DC formulation (0.105 ± 0.033 1/kg/cm²). In-vitro dissolution study showed that more than a 90%  of tannin was released within 30 and 60 min from tablets prepared by wet granulation and DC, respectively. Brittle fracture index data indicate that tablets prepared from granules showed less fracture, capping and lamination tendencies.

Conclusion: It is concluded that the desired flowability, compressibility and compactibility of Saraca indica bark powder can be obtained by direct compression and wet granulation techniques.