Gentle, controlled drying of highly potent pharmaceutical powders: the Microsphere case

The context: a high-precision technical challenge

In the pharmaceutical industry, spray drying is a well-established technology for producing powders used in oral solid dosage forms, inhalation formulations and other therapies involving challenges related to solubility and bioavailability. However, the resulting powders often require a secondary drying step to achieve the residual moisture and residual solvent levels specified for the product.


 
This step becomes particularly critical when working with:
 

• highly potent active pharmaceutical ingredients (HPAPIs) requiring high containment levels (up to OEB-4/5)

• temperature-sensitive compounds subject to degradation from thermal stress

• ultrafine powders (< 5/10 µm) with a high risk of agglomeration

Conventional drying technologies are often unable to meet all these requirements simultaneously without compromising product integrity.

The customer: Microsphere, an innovative CDMO

Microsphere is a pharmaceutical Contract Development and Manufacturing Organization (CDMO) specializing in spray drying, capsule filling and advanced particle engineering solutions. It supports global partners throughout both clinical development and commercial manufacturing.
 
In its manufacturing operations, Microsphere uses spray drying technology to produce powders with a controlled particle size distribution — often below 5/10 µm — for oncology, respiratory and neurological (CNS) therapies, as well as other advanced drug delivery systems.

The secondary drying system serves three specific purposes:
 

1. Reduction of residual solvent content

2. Improvement of powder stability

3. Batch homogenization across different sub-batches generated by spray drying

The solution: Planex® System by Italvacuum

To meet these requirements, Microsphere integrated the Planex® System developed by Italvacuum into its production line, selecting this technology as a dedicated secondary drying solution.


The Planex® System is a horizontal vacuum dryer equipped with a patented eccentric agitator featuring two independent movements:
 

• rotation around its own axis

• tangential rotation relative to the drying chamber

This unique configuration enables highly efficient and uniform mixing, even with very fine and delicate powders, while minimizing mechanical stress on the particles.

Customization: adapting to a critical application

Following installation, Italvacuum — in close collaboration with the Microsphere technical team — designed and implemented specific system modifications to make it suitable for handling highly potent pharmaceutical materials:
 

• Optimization for ultrafine powders (< 5/10 µm)

• Closed-loop loading and unloading systems with OEB-4/5 containment

• Advanced filtration solutions

• Improved overall containment performance

Key benefits of the implementation

Gentle, low-stress treatment The Zero Friction® eccentric agitation system provides dynamic movement with reduced mechanical impact, preserving particle integrity and reducing the risk of thermal degradation.

Simultaneous drying and homogenization The Planex® System performs drying and mixing in parallel, ensuring high batch uniformity — a critical factor when managing sub-batches from spray drying.

Precise particle size control The system prevents agglomeration and maintains the desired particle size distribution throughout the process.

Reduced process times Thanks to its high vacuum capacity, the system significantly accelerates solvent removal, reducing overall cycle times.

HPAPI containment The closed-loop loading and unloading configuration ensures full compliance with containment requirements for highly potent active pharmaceutical ingredients.

Validatable cleaning The design provides full accessibility for cleaning validation (swab testing) and simplifies the disassembly of internal components.

Conclusions

The implementation of the Planex® System in the Microsphere production line demonstrates how advanced vacuum drying technologies can overcome the limitations of conventional systems when handling critical pharmaceutical powders.

The collaboration between Italvacuum — with its expertise in the design of industrial drying systems — and Microsphere — with its advanced particle engineering expertise — has resulted in a tailor-made solution capable of addressing some of the most complex challenges in modern pharmaceutical manufacturing.

Would you like to know how the Planex® System can be integrated into your production process? Contact the Italvacuum team → marketing@italvacuum.com