Two flow-focusing streams for drug formulations and a third for compressed air to form a spray generate particle sizes below 100 nm, increasing the drugs’ solubility. |
Teams from the U.S.
and Germany
have developed a spray drying technique to fabricate drug formulations smaller
than 100 nm for pharmaceutical trials, improving the drugs’ solubility, or
bioavailability.
Over the last decade, the molecular
complexity of drugs has increased significantly, leading to poor solubility,
which means that the compounds can’t be used in the human body. To determine if
new formulations have potential as successful drugs, solubility tests are run
at an early stage of development. However, the amount of drug available for these
tests is usually very small.
One way to get around this problem is by
decreasing the compounds’ particle size. David Weitz from Harvard Univ.,
Cambridge, U.S., and colleagues, have done just that by developing a
microfluidic device made from poly(dimethylsiloxane), incorporating two
flow-focusing streams and a third for compressed air to form a spray, that can
generate particle sizes below 100 nm.
“We were searching for convenient
ways of creating drug nanoparticles to increase the bioavailability. Rapid
precipitation from solution through addition of a poor solvent is a simple
means of making small particles, but they tend to coarsen and become larger than
the desired nanometre size,” explains Weitz. “To prevent this, we
wanted to remove them from the solvent as quickly as possible and we thought
that drying the solvent would be a way to do so.”
