Pharmaceutical Technology Europe - June 2012 - (Page 10)

Advancing Unit Operations for Continuous Processing in Solid Dosage Manufacturing Although pharmaceutical production is a batch-processing operation, specific unit operations in solid-dosage manufacturing, such as milling or tablet compression, may be run in semicontinuous and continuous processing steps. The feasibility of developing continuous processes for specific unit operations requires advances in pharmaceutical equipment design and operation. For example, to make continuous mixing, granulation and drying possible for small-scale operations, such as in the pharmaceutical industry, systems need to be developed with limited or no start-up and shutdown waste to enable a steady state to be reached in an extremely short time. One advantage of continuous operations is the elimination of scale-up, which may be difficult overall and in specific operations, such as granulation. As hot-melt extrusion is gaining popularity for solubilisation of insoluble drugs, twin-screw extrusion is also gaining attention as a continuous alternative to traditional high-shear granulation. This continuous process enables faster throughput and easier scale-up. Ashland Specialty Ingredients recently presented results on how hydroxypropylcellulose (Krucel), povidone (Plasdone) and hypromellose (Benecel) performed in continuous low-temperature extrusion granulation compared with traditional wet granulation. The results showed twin-screw extrusion as a promising method for high-dose formulations and highlighted how tablets made by means of extrusion showed improved strength and low friability compared to traditional wet granulation, according to a company press release. Researchers at Ghent University in Belgium and Complutense University in Madrid recently evaluated the strengths and weaknesses of several complementary process analytical technology (PAT) tools implemented in a continuous wet-granulation process, which was part of a fully continuous from powder-to-tablet production line. The use of Raman and near infrared spectroscopy and a particle-size distribution analyser was evaluated for the real-time monitoring of critical parameters during the continuous wet agglomeration of an anhydrous theophylline−lactose blend. The solid-state characteristics and particle size of the granules were analysed in real-time and the critical process parameters influencing these granule characteristics were identified. The temperature of the granulator barrel, the amount of granulation liquid added and, to a lesser extent, the powder feed rate were the Patricia Van Arnum parameters influencing the solid state of the API. The researchers reported that a higher barrel temperature and a higher powder feed rate resulted in larger granules. PTE Patricia Van Arnum is executive editor of Pharmaceutical Technology. An extended version of this article is available at” PharmTech.com/AdvancingUnit 2 Analytical Stability 11 Freeze Drying Optimisation 3 Aseptic Filling 12 Hot Melt Extrusion 4 News 14 Interview 10 Manufacturing 16 Ask the Expert http://www.PharmTech.com/AdvancingUnit

Table of Contents for the Digital Edition of Pharmaceutical Technology Europe - June 2012

Pharmaceutical Technology Europe - June 2012
Contents
Analytical Stability
Aseptic Filling
News
Blogs Abridged
Cleaning
Manufacturing
Freeze Drying Optimisation
Hot Melt Extrusion
Column Crunch: Biomanufacturing; European Regulators Struggle
Interview
Ask the Expert

Pharmaceutical Technology Europe - June 2012