Microsphere Formulation with the PSL Microsphere Refiner


Decades of experience in sterile production has led PSL to develop unique filtration solutions for microsphere formulation, from small scale processes up to production.



Microspheres are small spherical particles, having a required size range (typically 5µm up to 250µm). These particles can be manufactured from various natural and synthetic materials such as polymer microspheres. New applications for microspheres are discovered every day from coating to cosmetics and cancer research.  PSL has developed process solutions for this type of drug delivery, as biodegradable polymer microspheres can work as miniature time release capsules for parenteral drugs, within pharmaceutical and biotechnology industries.  Along with these types of processes, other industry requirements have evolved utilizing the microsphere technology.



Microsphere production is experiencing a fast growing demand due to its revolutionary characteristics and applications. Blue chip pharmaceutical companies around the world are adopting this formulation method, usually developed by lab development contract organisations and research universities. The first applications for the pharmaceutical sector were developed 10 years ago mainly in the United States of America, where PSL was already a pioneering equipment manufacturer providing small scale sterile systems, specifically designed to suit the microsphere formulation.



Suspended microspheres obtained from various micro encapsulation processes require unique handling that differ from a typical filtration and drying operation. Following the synthesis stage, microspheres require being washed, classified by size, filtered then dried under appropriate conditions to gain the final free flowing injectable or inhalation microsphere product. Microspheres are random in size and need to be filtered and classified into the micron size range desired before drying. PSL Microsphere Refiners have been designed to meet these criteria from washing to classifying and drying.



With PSL's unique design, utilising side and bottom filtration, size classification is achieved. Classification being the most difficult task associated with Microsphere production. Typically with microsphere processes, large liquid volumes with a small ratio of suspended solids have to be handled.  Thus some processes require a scalping pre-filtration step in order to reduce the liquid volume and eliminate the oversized microspheres.  This is achieved with the PSL Scalping Filter prior to transfer into the PSL Microsphere Refiner.



Most microsphere processes require sterility, PSL solutions have been designed with Steam-In-Place and drainability capabilities.  The discharge is part of the sterility envelope.  PSL Microsphere Refiner is tiltable to accommodate a sterile discharge.



PSL have completed a number of worldwide projects using Microsphere filtration solutions from lab scale to commercial production. This complex process is now implemented more and more around the world by undisclosed pharmaceutical and biopharmaceutical companies. PSL is proud to participate to this great technological advancement that will improve the wellbeing of millions of suffering patients.



About PSL

Powder Systems Ltd (PSL) is an international manufacturer of filtration, drying and high containment isolator solutions for pharmaceutical, biopharmaceutical, chemical, laboratory, explosive and battery industries.



PSL has been established for 24 years and is an original pioneer of high containment systems such as isolators and gloveboxes. We have significant experience designing and engineering advanced containment processes for highly potent and valuable products including sterile, oncology, hormone and many other pharmaceutical compounds. PSL provides a full range of filtration, drying and contained isolator products for small scale production to full process systems.



Our products enable major blue-chip companies including the top 10 pharmaceutical organisations such as Pfizer, GSK, BMS and Sanofi Aventis to bring new generation drugs into the market place faster, using the latest technology in containment and production equipment.




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