Nanoembedded Microparticles for Stabilization and Delivery of Drug-Loaded Nanoparticles

Nanoembedded Microparticles for Stabilization and Delivery of Drug-Loaded Nanoparticles

Bohr A, Water J, Beck-Broichsitter M, Yang M


Nanoparticle-based pharmaceutical products are currently finding their way onto the market as a popular strategy to improve the therapeutic efficacy of numerous drugs, hereunder medications for a targeted treatment of severe diseases (e.g., cancer). Drug-loaded polymer and lipid nanoparticles are typically produced via solventbased methods and result in colloidal suspensions, which often suffer from physical and chemical instability (e.g., formation of aggregates) resulting in loss of functionality. There are various ways to stabilize such nanoparticlebased formulations including addition of ionic materials to provide electrostatic repulsion or polymer materials forming a steric barrier between the particles. However, for long-term stability often water needs to be removed to obtain a dry product. For this purpose atomization-based techniques such as spray-drying and spray freeze-drying are frequently used to remove water from the nanoparticle suspensions and to form tailored powder products (e.g., nanoembedded microparticles (NEMs)). NEMs provide an excellent vehicle for both stabilization of nanoparticles and delivery of the nanoparticles to their intended site of action. Excipients such as sugars and biocompatible polymers are used to prepare the surrounding, stabilizing matrix. Further, these “Trojan” vehicles are compatible with a wide range of therapeutic molecules, nanocarriers and applications for different routes of administration. The preparation, properties and stability of these NEMs are described in this review and their application and future development are discussed.

Keywords: Nanoembedded microparticles, drug delivery, spray freeze drying, nanomedicine, nanoparticles, spray drying

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Freeze Granulation of ceramic powders

Freeze Granulation offers the possibility to produce very soft, spherical granules which show an excellent flowability. The granules can be compressed to compacts of high homogeneity and they are completely redispersable. Freeze Granulation is a granulation technique which combines the advantages of spray drying and freeze drying. Hard granules are prevented by this technique excluding capillary forces during drying.

Please contact us if you would like to test-granulate your powders or chemicals.

Protein aerosol powders

Freeze granulation, as opposed to spray drying, has been shown to produce protein particles with light and porous characteristics, which offered powders with superior aerosol performance due to favorable aerodynamic properties, suitable granulation technology for protein inhalation powders.


Granule homogeneity

Migration and segregation of the constituents that is common in other granulating processes such as spray drying is avoided in Freeze Granulation. By instant freezing of small droplets critical ice crystal growth is avoided. The freeze drying where the liquid medium is sublimated ensures homogeneity preservation, limited oxidation and soft bonds within the granules. This provides the best possible condition for any subsequent processing such as easy pressing to homogenous compacts, easy re-dispersing in a liquid, sintering of catalytic particles, dosage processes etc.

Spray drying compared with Freeze Granulation

What is the difference between spray drying and Freeze Granulation? For more info, please go to our Pros & Cons.

The best way to find out if Freeze Granulation is suitable for your material is to let us do a test granulation. Freeze Granulation will be more expensive than spray drying as it is a two-step process.  The relative difference depends on the scale and Freeze Granulation is more suitable for small or medium size batches where the demands on granule quality is high whereas spray drying is most suitable for large scale processing.