<p>High shear wet granulation (HSWG) transforms fine powder blends into free-flowing granules with improved compression properties during the tabletting process. Granulation also enhances the uniformity of a blend, increases density and reduces dust levels, an important health and safety benefit. The pharmaceutical industry is one of several which rely heavily on HSWG processes, most especially in the manufacture of oral solid dosage forms.</p><p>A Quality-by-Design (QbD) approach in drug development and manufacture relies on data collection at relevant points in the process to control the critical quality attributes (CQAs) of the product.</p><p>Granules are typically an intermediate, rather than the end product, making it more difficult to identify the critical process parameters (CPPs) that impact the CQAs of the finished product. Research has shown that HSWG processes can be successfully optimised using at-line techniques such as dynamic powder testing, but continuous, real-time analysis has the ability to provide further information by measuring the wet granulated mass, in-process, without interrupting the granulation operation.</p><p>The Lenterra Flow Sensor (LFS) System (Lenterra Inc. USA) is a Process Analytical Technology (PAT) that provides high frequency, high resolution in-line flow force measurement. In this article we look at how it work and examine its potential application in HSWG monitoring and control. Research using an FT4 Powder Rheometer&amp;reg; (Freeman Technology, UK) suggests that both can be used at different stages of development and manufacturing to optimise HSWG processes.</p><div style="text-align: center;"><img src="http://www.microbiozindia.com/fck/image/7778.png" width="570" height="326" alt="" /></div>rnFigure 1: FT4 Powder Rheometer (left), Lenterra Drag Force Flow Sensor (right)rn<p><strong><br />rnThe challenge of HSWG</strong></p><p>During HSWG a blend of active ingredients and excipients are energetically combined with liquid, often water, to form relatively large, homogeneous granules. These undergo further processing to produce an optimal feed for downstream tablet manufacture. A typical objective for tableting would be to produce homogeneous granules that enable high throughput on the press and result in tablets with target CQAs.</p><p>The properties of granules are controlled through manipulation of a number of processing parameters, including:</p><ol><li>Quantity of water added</li><li>Water addition rate</li><li>Impeller/hopper speed</li><li>Granulation time</li></ol><p>Altering these variables enables the optimisation of granule properties and is usually a lengthy empirical process that relies on the implementation of statistical design-of-experiment (DoE) studies to correlate CPPs with the critica