Pharmaceutical Spray drying is a very fast method of drying due to the very large surface area created by the atomization of the liquid feed. As a consequence, high heat transfer coefficients are generated and the fast stabilisation of the feed at moderate temperatures makes this method very attractive for heat sensitive materials. Five things you might not know about spray drying
Spray drying provides unprecedented particle control and allows previously unattainable delivery methods and molecular characteristics. These advantages allow exploration into employing previously unattainable delivery methods and molecular characteristics.
GEA Niro is the market leader in spray drying technology and has spent more than a decade refining the technology specifically for use within the area of final solid dosage drug forms.
- Spray drying is suitable for heat sensitive materials
Spray drying is already used for the processing of heat sensitive materials (e.g. proteins, peptides and polymers with low Tg temperatures) on an industrial scale. Evaporation from the spray droplets starts immediately after contact with the hot process gas. Since the thermal energy is consumed by evaporation, the droplet temperature is kept at a level where no harm is caused to the product.
- Spray drying turns liquid into particles within seconds
The large surface of the droplets provides near instantaneous evaporation, making it possible to produce particles with a crystalline or amorphous structure. The particle morphology is determined by the operating parameters and excipients added to the feed stock.
- Spray drying is relatively easy to replicate on a commercial scale
GEA Niro has been producing industrial scale spray drying plants for well over half a century. Our process know-how, products and exceptional facilities put us in a unique position to advise and demonstrate how products and processes will behave on a large scale.
- Spray drying is a robust process
Spray drying is a continuous process. Once the set points are established, all critical process parameters are kept constant throughout the batch. Information for the batch record can be monitored or logged, depending on the system selected.
- Spray drying can be effectively validated
GEA Niro has extensive experience of supplying spray dryers and processes that have been validated and approved by regulators. The precise control of all critical process parameters in spray drying provides a high degree of assurance that the process consistently produces a product that meets set specifi cations.
The spray drying process
Spray drying is a very fast method of drying due to the very large surface area created by the atomization of the liquid feed and high heat transfer coefficients generated. The short drying time, and consequently fast stabilisation of feed material at moderate temperatures, means spray drying is also suitable for heat-sensitive materials.
As a technique, spray drying consists of four basic stages:
- Atomization: A liquid feed stock is atomized into droplets by means of a nozzle or rotary atomizer. Nozzles use pressure or compressed gas to atomize the feed while rotary atomizers employ an atomizer wheel rotating at high speed.
- Drying: Hot process gas (air or nitrogen) is brought into contact with the atomized feed guided by a gas disperser, and evaporation begins. The balance between temperature, flow rate and droplet size controls the drying process.
- Particle formation: As the liquid rapidly evaporates from the droplet surface, a solid particle forms and falls to the bottom of the drying chamber.
- Recovery: The powder is recovered from the exhaust gas using a cyclone or a bag filter. The whole process generally takes no more than a few seconds.
Read further about spray drying and spray dryer technology from GEA Niro here.
From drug development to drug production
As an experienced process development partner, GEA Niro can help meet your needs in many areas. From investigating how spray drying can enhance your drug formulation, through process development, producing clinical trials material and large-scale production tests, Niro's experienced technologists and equipment are there to help you.