| Initial Dry Mixing | Distribute the main powder and minor ingredients before liquid addition or further processing. | Collect 10 samples from representative locations, including the upper, middle, lower, center, and discharge zones. | 100% of the target concentration | 90%–110% of the target concentration | ≤5.0% | Accept when the RSD is ≤5.0% and the individual results meet the predefined range. | Increase mixing time only after checking fill level, impeller condition, and sampling technique. |
| Final Powder Blend | Achieve a consistent composition before filling, compression, packaging, or transfer to the next process. | Collect 10 samples at different time points and discharge locations. | 100% of the target concentration | 95%–105% of the target concentration | ≤5.0% | Accept when the mean is close to target and the RSD remains at or below 5.0%. | Review mixing sequence, powder flowability, segregation risk, and discharge configuration if results fail. |
| Liquid–Solid Dispersion | Disperse a solid ingredient uniformly throughout a liquid carrier and reduce concentration gradients. | Collect 10 samples from the top, middle, bottom, and outlet stream after the defined mixing time. | 100% of the target concentration | 90%–110% of the target concentration | ≤5.0% | Accept when sampling locations show no systematic high or low concentration pattern. | Check agitation speed, vortex formation, addition rate, and the risk of settling during sampling. |
| Liquid Blending | Produce a consistent liquid mixture for filling, coating, dosing, or downstream processing. | Collect 10 samples from multiple vessel heights and the discharge line. | 100% of the target concentration | 95%–105% of the target concentration | ≤5.0% | Accept when concentration uniformity is maintained from the vessel to the outlet. | Inspect impeller placement, tank geometry, recirculation, temperature, and viscosity changes. |
| Scale-Up Verification | Confirm that a larger mixing machine delivers comparable blend uniformity to the established process. | Use the same number of representative sampling points and the same analytical method used during development. | 100% of the target concentration | Within the approved process specification | ≤5.0% | Accept when scale-up results meet the predefined uniformity and process-performance criteria. | Compare power input, mixing time, fill ratio, shear, and material-transfer conditions with the smaller scale. |
| Routine Batch Monitoring | Maintain repeatable quality and identify drift before it affects production output. | Use a documented sampling plan with periodic checks at defined critical locations. | 100% of the target concentration | Within the approved process specification | ≤5.0% | Accept when the result meets both the individual-value specification and the RSD limit. | Trend RSD, mean concentration, mixing time, load size, and equipment settings for continuous improvement. |