Thank you for the clarification, Marco, and the additional information (and your Engish is 20 times better than my Italian 
).
I think this is certainly possible, that the containers might be suggestive of compound drugs. It might even be the most likely explanation.
I've often thought about what they might represent.
Another idea that came to mind was that the containers might represent categories of plants. For example, some plants are used for preservation, some for baked goods (e.g., certain spices), others were used for savory foods like soup and stew, some plants were used as ointments, some were cosmetic, others were medicinal, some were purely talismanic, some were used as perfumes, others for burning in censors.
Or the containers might be a signal (by that I mean the shape of the container might be meaningful in a way that is symbolic rather than literal) as to how a plant was to be prepared (ground, dried, cured, or prepared as a tincture), or perhaps how it should be stored (again, in a symbolic rather than a literal way). Some of them could even be related to pigments.
They are very beautiful containers. The average person would never see anything as nice as these. That's why I wonder if they might be symbolic in some way. They progress from more simple ones (almost like reading tubes) toward some that are not the normal shape for storage containers. Not even the fanciest apothecary jars look like these except ones used for very expensive and precious items like Balsam, myrhh (a word they used for several different resins), or expensive perfumes or ointments. A few of them look like containers that would be specially crafted for a king and would not be seen outside the circle of nobility.
).MarcoP wrote:More importantly, most of the rows of plants begin with a labelled container that could represent the compound produced by using those simples. I think Touwaide finds this original iconographic system suggestive of the knowledge of Galen's works about compound drugs (of which I know nothing).
I think this is certainly possible, that the containers might be suggestive of compound drugs. It might even be the most likely explanation.
I've often thought about what they might represent.
Another idea that came to mind was that the containers might represent categories of plants. For example, some plants are used for preservation, some for baked goods (e.g., certain spices), others were used for savory foods like soup and stew, some plants were used as ointments, some were cosmetic, others were medicinal, some were purely talismanic, some were used as perfumes, others for burning in censors.
Or the containers might be a signal (by that I mean the shape of the container might be meaningful in a way that is symbolic rather than literal) as to how a plant was to be prepared (ground, dried, cured, or prepared as a tincture), or perhaps how it should be stored (again, in a symbolic rather than a literal way). Some of them could even be related to pigments.
They are very beautiful containers. The average person would never see anything as nice as these. That's why I wonder if they might be symbolic in some way. They progress from more simple ones (almost like reading tubes) toward some that are not the normal shape for storage containers. Not even the fanciest apothecary jars look like these except ones used for very expensive and precious items like Balsam, myrhh (a word they used for several different resins), or expensive perfumes or ointments. A few of them look like containers that would be specially crafted for a king and would not be seen outside the circle of nobility.