Predicting the impact of adhesive forces on particle mixing and segregation

Assessment of Resonant Acoustic Mixing for Low-Dose Pharmaceutical Powder Blends

Obtaining a homogeneous low-dose pharmaceutical powder blend without multi-step processing remains a challenge. One promising technology to address this risk is resonant acoustic mixing (RAM). In this study, the performance of a laboratory resonant acoustic mixer (LabRAM) was studied at low active pharmaceutical ingredient (API) concentrations (0.1-0.5% w/w), using three commercial grades of a model API (Acetaminophen) and diluents with varying physical properties. The performance was assessed by evaluating blend uniformity (BU) and capsule content uniformity (CU) as a function of mixing time. Overall, the LabRAM achieved acceptable BU in a single step even at 0.1% w/w drug loading. A reduction in API primary particle size led to improved mixing efficiency and uniformity. Moreover, the presence of surface cavities in the diluents used appeared to have led to improved uniformity. The results demonstrated that RAM could achieve uniform powder blends without multi-step processing, for low-dose formulations.

Research on the Wear Behavior of the Fixed Cone Liner of a Cone Crusher Based on the Discrete Element Method

Taking reducing the wear of the fixed cone liner of a cone crusher as the starting point, the movement and geometry parameters of the cone crusher are studied using the discrete element method. To improve the service life and working efficiency of the whole cone crusher. The UG model and discrete element Yade model of the cone crusher are established, and the different shapes of the tin ore are represented using Yade's preprocessor through eight different ways of particle combination and superposition. The static friction coefficient between the manganese ore and the cone crusher is studied and calibrated using the slope method. The relative error between the Yade and test results is 1.58%, and the calibration result is 0.44. The repose angle of the manganese ore is studied using the collapse method. The repose angle increases with the increase of the static friction coefficient and the dynamic friction coefficient, but the change trend is different. The effect of the dynamic friction coefficient on the repose angle is obviously greater than that of the static friction coefficient. The dynamic friction coefficient obtained by Yade is 0.042. Taking the swing distance, rotating speed, and bottom angle of the fixed cone as the orthogonal experimental factors of Yade, the regression equation of the fixed cone liner was obtained through the nonlinear processing of SPSS 25.0. According to Matlab R2017b, the influences of the swinging distance, rotating speed, and bottom angle of the fixed cone on the fixed cone liner are obtained. According to Yade's research results, the order of the influence degree of liner wear is: the rotating speed of moving cone, the swinging distance of the fixed cone, and the base angle of fixed rotation. When the swinging distance of the fixed cone is 146 mm, the rotating speed of the moving cone is 198 rpm, the fixed rotation bottom angle is 28°, and the minimum value of the liner wear is 23 mm. Yade's results are consistent with the change trend of the wear amount of the bushing obtained from the test. The research results show the correctness of using the Yade method to study the wear of the fixed cone liner of a cone crusher, which provides a theoretical basis for reducing the wear of the fixed cone liner of a cone crusher, and puts forward a new method to study the wear of relevant parts of a fixed cone crusher. At the same time, the research results are of great significance for achieving energy-saving in mining enterprises.

Towards integrated drug substance and drug product design for an active pharmaceutical ingredient using particle engineering

A novel experimental approach describing the integration of drug substance and drug production design using particle engineering techniques such as sonocrystallization, high shear wet milling (HSWM) and dry impact (hammer) milling were used to manufacture samples of an active pharmaceutical ingredient (API) with diverse particle size and size distributions. The API instability was addressed using particle engineering and through judicious selection of excipients to reduce degradation reactions. API produced using a conventional batch cooling crystallization process resulted in content uniformity issues. Hammer milling increased fine particle formation resulting in reduced content uniformity and increased degradation compared to sonocrystallized and HSWM API in the formulation. To ensure at least a 2-year shelf life based on predictions using an Accelerated Stability Assessment Program, this API should have a D [v, 0.1] of 55 μm and a D [v, 0.5] of 140 μm. The particle size of the chief excipient in the drug product formulation needed to be close to that of the API to avoid content uniformity and stability issues but large enough to reduce lactam formation. The novel methodology described here has potential for application to other APIs.