OBJECTIVE  To study the preparation technology based on quality by design (QbD) concept of Erdong decoction particles, and to control its quality.

METHODS  Design L9(3⁴) orthogonal test method, and the extraction process of Erdong decoction was optimized by AHP-CRITIC mixed weighted method with the extract rate, index component transfer rate and total polysaccharide as evaluation indexes. Taking ratio of briquetting, dissolution rate, angle of repose and moisture absorption rate as indexes, the central composite design-response surface methodology method combined with entropy weight method was used to optimize the forming process of Erdong decoction granules. The relative homogeneity index, bulk density, vibration density, moisture, hygroscopicity, angle of reposition and Hausner ratio were used as indicators to establish a physical fingerprint to evaluate particle quality consistency.

RESULTS  The optimal extraction process of Erdong decoction was to add 12 times of water without soaking and extract it 3 times for 30 min each time. The mean comprehensive score of the three batches of repeated validation tests was 54.24, and the RSD was 1.09%. The optimum molding process of Erdong decoction granules was as follows: the ratio of dry paste powder to auxiliary material was 1∶0.6, the volume fraction of wetting agent was 87%, the amount of wetting agent was 16%, and it was dried at 80 ℃ for 30 min. The similarity of physical fingerprints of 5 batches of particles was>0.99.

CONCLUSION The method is stable and feasible, which can provide direction for the industrial production of Erdong decoction granules and the further research of this preparation.