Near-infrared methods for the identification of tablets in clinical trial supplies

Near-infrared reflectance analysis (NIR) methods have been developed for the confirmation of the identity of blister-packed tablets for clinical trial supplies. Three approaches are described: (1) presentation of single exposed tablets from blisters directly to the optical window; (2) presentation of unopened opaque blister-packed tablets directly to the optical window of the NIR instrument; and (3) use of a fibre-optic accessory to examine tablets through unopened opaque blister packs. For clinical purposes, all tablets in this trial were manufactured to match the appearance of one another. Tablets containing four strengths of an experimental drug (2, 5, 10 and 20% w/w of the active), a marketed product as a clinical comparator (80% w/w of the active), and a placebo were investigated. The NIR methods were developed by chemometrically building a library with second derivative spectra for each tablet type. Library validation and test data are presented along with a comparison of the three sample presentation techniques. The scope and limitation of each sample presentation technique are discussed.