DETERMINATION OF MOISTURE IN HARD GELATIN CAPSULES USING NEAR-INFRARED SPECTROSCOPY - APPLICATIONS TO AT-LINE PROCESS-CONTROL OF PHARMACEUTICS

A method is proposed in which diffuse reflectance near-infrared spectr oscopy (NIR) is applied in an at-line process analytical interface to determine moisture content in bulk hard gelatin capsules. Capsule samp les were equilibrated at various relative humidities and the moisture contents were determined using loss on drying (LOD). Different multiva riate calibration methods using multiple linear regression (MLR) and p artial least squares regression (PLSR) and various spectral pretreatme nts were compared. No sample pretreatment was required and the analysi s time was 1-2 min. The investigated range for the moisture determinat ion was 5.6-18.0% w/w and the root mean square error of prediction (RM SEP) value was 0.1% w/w (C) 1997 Elsevier Science B.V.