The silica coating technology for inhlational drug delivery is not that common. I don't know of any US products that plan to use it - the DPI (dry powder inhalation) players in the US are mostly relying on creating hollowed out spheres of drug (eg. insulin) to stop Van der Waals clumping.
However, there is a group in Germany that are experimenting with silica: http://www.mvt.uni-erlangen.de/Personen/MLinsenbuehler/Forschung.html
Note how difficult it was for them to coat lactose particles with silica and not simply end of with a messy mixture of lactose and silica.
Look at the SEMs - each lactose particle has a perfect coating of silica. There is no sign of any extraneous silica or secondary phase. They had to go to great lengths to achieve this - they oppositely charged the silica and lactose and mixed them in liquid nitrogen. The charged silica was attracted to the oppositely charged lactose. There are other ways of doing this as well. The point is - it's not easy.
Invert emulsions? IIRC that was around in 1985.
Note how difficult it was for them to coat lactose particles with silica and not simply end of with a messy mixture of lactose and silica.
It's not bucket chemistry, but it didn't look that bad to me. In fact, it was a fairly straightforward process requiring relatively simple equipment compared to, for example, a silicon wafer fab or nuclear weapons development.
Iraq has a number of very well educated technologists. Saddam would give them all the money they needed. Equipment isn't that hard to get and it doesn't cost that much. You can buy a $36k Leica SEM on eBay. Chump change for Osama bin Laden. Need a cryogenic grinder? Desktop models are available. It's America. The base information is in scientific journals all over the world. I don't see what you described as anything more than a barrier requiring time and money. Given that Saddam was on his way to nuclear weapons, a process that requires VASTLY more expensive and bulkier equipment, why should coating particles be so far beyond a determined effort?