Internal standard variability: root cause investigation, parallelism for evaluating trackability and practical considerations

Affiliations

• ¹ Division of Product Quality Research, Office of Testing & Research, Office of Pharmaceutical Quality, Food & Drug Administration, Center for Drug Evaluation & Research, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.
• ² Division of New Drug Study Integrity, Office of Study Integrity & Surveillance, Office of Translational Sciences, Food & Drug Administration, Center for Drug Evaluation & Research, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.
• ³ Office of Study Integrity & Surveillance, Office of Translational Sciences, Food & Drug Administration, Center for Drug Evaluation & Research, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.