Technical Mechanics and Bioavailability
A significant portion of new chemical entities faces challenges related to low solubility. Spray drying addresses this by "freezing" the drug molecules in a disordered, amorphous state within a polymer matrix. This prevents the drug from crystallizing, which would otherwise limit its absorption in the gastrointestinal tract. The resulting powder is often highly stable and can be easily processed into tablets or capsules, providing a reliable path for oral delivery of complex molecules.
In the field of inhalation therapy, particle size is the determining factor for where a drug lands in the respiratory tract. Particles must generally be between one and five microns to reach the deep lung (alveoli). Spray drying offers unparalleled control over these parameters, allowing engineers to produce hollow or porous particles with low density. These engineered particles stay suspended in the airflow more effectively, improving the efficiency of dry powder inhalers and reducing the dose required for therapeutic effect.