Spray drying has become one of the most successful particle engineering technologies for improving drug bioavalability through the amorphous solid dispersion platform.
Spray drying is a continuous process that can be used for multiple applications. Over the last 10 years, the technology has been used for the production of solid dispersions and is the fastest growing platform to overcome the solubility issues related to oral drugs, it is also relevant to inhalable particles, specialty excipients and for the isolation of thermally labile products.
How it works
The feed (a solution, emulsion or suspension) is atomized into hot nitrogen leading to flash (rapid) drying and particle formation. The particles are then separated in a cyclone and/or filter bag.
Amorphous materials (drug + polymer) used to overcome solubility limitations of BCS class 2 and 4 drugs. Both drug and polymer need to dissolve in the solvent system.
Crystalline drug encapsulated with a coating polymer. For example, enteric polymers can be used to protect the drug from the gastric conditions or for enhanced delivery to the site of maximum absorption. Similar approaches can be used for taste masking and for protecting the drug from physical environments (e.g. light, moisture).
Ability to control particle size, morphology and other properties with direct effect in Fine Particle Fraction (FPF) and lung deposition.
Spray drying is also the method of choice for materials that cannot withstand abrasion or shearing, like biologics. Hence, it is the preferred option for new the generation of inhaled formulations for biologics – e. g. inhaled insulin formulation in Affrezza (MannKind) and Exubera (Pfizer).
Isolation of thermally labile materials
Due to the gentle nature of the process it can be used to isolate materials that degrade during conventional isolation processes.
Learn more about Spray Drying, with the following article by Hovione's experts:
Applying Quality by Design to spray drying - The role of empirical and mechanistic modeling
Source: Chemistry Today, March/April 2013