What’s in a Tablet? Extraction and Spectroscopic Identification of Pharmaceutical Unknowns

• Published in: Journal of chemical education Vol. 99; no. 8; pp. 3024 - 3029
• Main Authors: Kessler, Hannah, Russo, Christopher M., Fumo, Vincent, O’Reilly, Matthew C.
• Format: Journal Article
• Language: English
• Published: Easton American Chemical Society and Division of Chemical Education, Inc 09.08.2022; American Chemical Society
• Subjects: Chemical reactions; Familiarity; Identification; Infrared spectroscopy; Laboratory Experiments; Liquid-liquid extraction; Molecules; NMR spectroscopy; Organic chemistry; Pharmaceuticals; Reaction products; Science Experiments; Science Instruction; Science Laboratories; Spectrum analysis; Students; Tablets; Vacuum filtration; NMR Spectroscopy; Laboratory Instruction; IR Spectroscopy; Student-Centered Learning; Second-Year Undergraduate; Drugs/Pharmaceuticals; Organic Chemistry
• ISSN: 0021-9584; 1938-1328
• DOI: 10.1021/acs.jchemed.2c00225

Spectroscopic characterization of molecules is typically reinforced in the organic chemistry teaching laboratory via the analysis of reaction products by NMR and IR, and initial coverage of these topics can include experiments involving the identification of unknown compounds. To combine the unknown identification component with common laboratory techniques and relevant biologically active compounds, an experiment was developed allowing students to identify the active pharmaceutical ingredient present in various unknown tablets. The protocol involves pulverization of the unknown tablets, solid–liquid extraction, vacuum filtration, liquid–liquid extraction, and solubility tests prior to analysis via IR and NMR spectroscopy. Ultimately, this laboratory experiment provides a platform for students to reengage with many techniques covered in introductory organic chemistry laboratory experiments while gaining exposure and familiarity with spectroscopic methods.