Uses of Near-Infrared Spectroscopy in Pharmaceutical Analysis

Abstract

Near-infrared (near-IR, NIR) spectroscopy has been a regularly used technique in agriculture and textile manufacturing for some years 1–61. However, the pharmaceutical industry has been slow to accept near-JR as an everyday analytical process. One reason may be its lack of primary absorption bands. All NIR absorbances are overtones of bands originating in the midrange infrared spectrum (4000–17000 nm). In addition, most of the near-JR spectrum of organic compounds (800–3500 nm) is attributable to combinations of the aforementioned over-tones. These “shortcomings” are more than compensated for by the attributes of near-IR instrumentation. Several excellent reviews have recently been published on the theory and instrumentation involved in near-IR reflectance analysis (NIRA) 7–10].