Blending

Overview

Whether performed in batch or continuous mode, the goal of a blending operation is to achieve a uniform mixture composition within a defined volume. Under-blending leads to poorly dispersed API and variance in product efficacy while over-blending results in manufacturing inefficiency. Thus, the major question for a blending operation is endpoint monitoring. Representative sampling is critical in achieving robust control of blend uniformity. Inline spectroscopic PAT is now widely used rather than grab samples for laboratory analysis because it offers the ability to measure more of the volume and provide a time-course of the blending operation without needing to grab samples. Despite the advantages of PAT in monitoring and controlling blend uniformity, the sample-based effects from the particles’ size, shape, composition, and dispersion that affect grab sampling also affect inline measurements. There are additional measurement-based considerations that include the sampling volume of the PAT probe, effects of heterogeneity on the spectra, and risk of particle adhesion on the probe window.

These combined sample-based and measurement-based effects underscore the importance of reducing variance in the PAT‑sampled volume while being able to measure as much in the blend as possible. Randomized measurements of defined volume are a proven approach to improving spectroscopic PAT robustness. The µSolis™ samples a powder or granule stream, creates a uniform volume for presentation to a spectroscopic PAT probe, and then wipes the powder away from the probe window. The µSolis™ integrates with industry-leading blending equipment including the Gericke Continuous Mixers for blend uniformity measurements at the output, with potential to divert out of specifications blends.