Dear Jasman, it is possible. For this you need to take into account several aspects.
1- evaluation of the particle size of the starting plant drug.
2- solvent system best suited for high extractive efficiency
3- consider the influence of the mill in the production of the powder of the vegetable drug (there are mills that produce finer powders).
4-to evaluate the influence of particle size on the extractive efficiency of its constituents
5-evaluate which drying system to use in obtaining a dry powdered extract (spray drier, freeze-drying, jet bed, frezze dried ...)
6- depending on the drying system to evaluate drying adjuvants (colloidal silicon dioxide, cellulose, maltodextrin, etc.)
7-depending on the drying system consider specific instrument such as spray drier atomizer nozzle diameter.
Anyway, as your question was quite general I did not have a very detailed answer, but there are several aspects that should be considered in obtaining an extract whose powder is on the nanometer scale.