Rationale

Standard E2891 has been reviewed per ASTM's 5-year cycle and found to be technically sound with guidance that remains relevant to current pharmaceutical development and manufacturing practices. This revision removes all references to E2474 (Practice for Pharmaceutical Process Design Utilizing Process Analytical Technology), which was withdrawn by ASTM in 2020, from Sections 2.1 and 4.3. Minor editorial improvements address punctuation, grammar, and consistency issues identified during the review process.