Extrusion-spheronisation method was used to prepare Rhus chinensis total phenolic acid pellets. The formula and preparation of R. chinensis total phenolic acid pellets were optimized. The formulas( drug loading capacity,diluent,wetting agent and anti-sticking agent) were determined by the single factor test with yield,appearance and performance as the indexes. The preparation was optimized by Box-Behnken design and response surface method,with the rate of extrusion,rate of spheronization and time of spheronization as the independent variables and the overall desirability value of yield,friability and roundness as the dependent variables. The optimal formula of pellets was as follows: drug loading capacity 28. 7%,MCC-lactose 9 ∶1,silicon dioxide as anti-sticking agent,and 60% ethanol as wetting agent. The optimal preparation was determined as follows: the rate of extrusion was 43 r·min-1,the rate of spheronization was 1 800 r·min-1,and the time of spheronization was 4 min. The absolute deviation between predicted value and estimated value under the conditions was less than 5. 0%,with a high degree of model fit. The preparation parameters obtained were accurate,reliable and reproducible. Under scanning electron microscopy( SEM),R. chinensis total phenolic acid pellets were uniform in diameter,round and smooth. The optimal formulation and process are stable and feasible for preparing R. chinensis total phenolic acid pellets.
Keywords: Box-Behnken response surface optimization method; Rhus chinensis; extrusion-spheronisation method; pellets; total phenolic acid.