Impact of co-processed excipient particles solidity and circularity on critical quality attributes of orodispersible minitablets

Abstract The selection of appropriate functional co-processed excipient (CPE) is a crucial stage in orodispersible minitablets (ODMTs) development. This paper aimed to identify the most important morphological attributes influencing the flowability and homogeneity of powder mixtures and minitablets final quality. Our research included the use of the laser diffraction method, the microscopic automated imaging technique and a flowability tester. All powder parameters examined were divided into two groups: those affecting mixture homogeneity or flowability. A Pearson's correlation matrix revealed a strong relationship between both, especially in terms of solidity-circularity and convexity-circularity pairs (r = −0.71, p = 0.010 and r = 0.93, p = 0.000 respectively). An analysis of model mixtures confirmed that high solidity values of the CPE support final mixture homogeneity and accordingly high circularity values support its flowability. In conclusion, solidity and circularity were indicated as the most critical morphological parameters, which have to be analyzed to define the best possible ODMTs formulation.