An increasing number of compounds in the drug development pipeline (>70%) are poorly soluble in water, and also in organic solvents. Spray drying is commonly used to increase bioavailability, but these ‘brick dust’ compounds require additional innovative steps if spray drying is to yield a commercially attractive process.
In this webinar, we discuss three enabling technologies designed to improve drug solubility in organic solvents for spray drying. One relatively simple way is to heat a drug slurry to a temperature below the solvent’s boiling point, which increases its solubility. A more creative process, Temperature Shift, also takes advantage of the solubility versus temperature curve. An in-line heat exchanger is used to rapidly increase the temperature of the solution above the boiling point immediately before atomization, dissolving the drug at a higher concentration. The third technology uses volatile processing aids, with no need for heating or other changes to the normal spray drying process. Ammonia, acetic acid, and formic acid all can be used in small quantities in methanol to ionize the drug, increasing its solubility. As these aids are volatile, they will be removed during secondary drying.
The significant increases in solubility provided by these three technologies can be enabling for compounds with poor solubility. In addition, the increased throughput has the additional benefit of reducing solvent consumption, cycle times, and costs.
Key Learning Objectives:
- Learn three technologies that increase organic solvent solubility, and how to implement them in spray drying processes
- Define the advantages and risks of each technology, and understand selection criteria for individual active pharmaceutical ingredients
- Determine the impact of these processes on throughput, and how they can save time and money