The wide use of wet granulation in the pharmaceutical industry and the effect of binder on the granule size have inspired the development of a multivariate mathematical model to determine the moisture content of pharmaceutical powders. The granule size affects the granule flowability, drug delivery, and tablet hardness. Off-line determination of moisture content using near Infrared (NIR) spectroscopy with multivariate analysis was the first step for implementation of in-line moisture measurements during the wet granulation process. In-line moisture measurements from NIR spectrometer is a technique that would be applied in pharmaceutical process analytical technology (PAT). Wet granulation of monohydrated and anhydride lactose was carried out with a water and Povidone solution. The studied factor was binder viscosity, which had values of 1 cP, 2.5 cP and 5 cP. The samples were analyzed in a NIR region from 7154.4 to 4575.6 cm-1. The NIR technique indicated high precision with a standard deviation of about 0.143% w/w and 1.61% relative standard deviation. The accuracy indicated by the root mean standard error prediction (RAMSEP) was 0.34 % w/w.

Keywords: Wet granulation; Moisture content; Near infrared; PAT