Process understanding is one of the key elements in todays pharmaceutical industry thanks to FDAs "Pharmaceutical cGMPs for the 21st Century: A Risk-Based Approach." However,for many generic pharmaceutical companies,utilization of Process Analytical Technology(PAT)is a huge mountain that is almost impossible to climb because of the technical difficulties,the regulatory uncertainties,and costly and long development cycle.For solid finished dosage units,controlling of the powder blending process is a critical operation for pharmaceutical manufacturing under cGMP regulation.Insufficient blend time results in the active ingredient not being properly mixed with excipients while excessive blend time can result in deblending which negatively impacts content uniformity.