Applications of terahertz spectroscopy to pharmaceutical sciences.
The application of terahertz pulsed spectroscopy within the US Food and Drug Administration's (FDA's) recent process analytical technology (PAT) initiative is considered. As a case study the potency levels in paracetamol (4-acetamidophenol) and aspirin (acetylsalicylic acid) test tablets have been recovered from the terahertz absorption spectra using a multivariate partial-least-squares (PLS) calibration model. Root-mean-square errors of cross-validation (RMSECVs) of 2.85% and 3.90% were obtained for paracetamol and aspirin, respectively. Information about other excipients can also be obtained; for example, using the strong lactose absorption lines in the tablets, RMSECVs of 3.65% and 4.30% could be recovered from the paracetamol and aspirin samples, respectively. As active ingredients may also change their solid-state form during formulation processing or storage and as this can adversely affect the final dosage performance, monitoring of pharmaceutical ingredients is essential for a 'right-first-time' philosophy within the industry. Terahertz pulse spectroscopy is a high-throughput technique with many areas of potential exploitation in the pharmaceutical industry; these issues are discussed in this paper.
Taday
Philip F
PF
TeraView Limited, 302/304 Cambridge Science Park, Milton Road, Cambridge CB4 0WG, UK. philip.taday@teraview.com
D000082:Acetaminophen / Q000032:analysis* / Q000737:chemistry / Q000592:standards; D000465:Algorithms; D001241:Aspirin / Q000032:analysis* / Q000737:chemistry / Q000592:standards; D002626:Chemistry, Pharmaceutical / Q000295:instrumentation / Q000379:methods*; D004340:Drug Contamination / Q000517:prevention & control*; D007259:Infrared Rays; D008872:Microwaves; D011785:Quality Assurance, Health Care / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000295:instrumentation / Q000379:methods*
D000082:Acetaminophen; D001241:Aspirin