Objective:Nine batches of Sanye particles

which prepared by changing fluidized bed process conditions

were taken as the research objects

and tensile strength is the main quality attribute of products to identify critical quality attributes and establish the design space(DS). Method:Orthogonal test was carried out to prepare different kinds of Sanye particles and their powder properties of the particles were determined.Orthogonal partial least square(OPLS) was used to establish the relational model between the powder properties and tensile strength.According to the characteristics of comprehensive variables extracted by OPLS

then independent variables were to find out

which had the strongest explanatory effect on the tensile strength

then we drew contour maps between independent variables and tensile strength to find the DS. Result:The median particle size(D50) and the porosity(ε) were identified as critical quality attributes.Relational models between D50 and ε with tensile strength were established

in the case of tensile strength range being fixed

the appropriate DS was found as 75.7% < ε < 78.2%

0.390 mm < D50 < 0.582 mm. Conclusion:The established OPLS can determine the influence of various factors on tensile strength

and the fitting effect is good.The established DS is clear

which can provide basis for establishing the technological parameters of fluidized bed granulation.