Tulp was both a surgeon and mayor of Amsterdam. As such he was responsible for inspections of apothecary shops. Thanks to new shipping routes, pharmacists in Amsterdam had access to many exotic herbs and spices from the East,  from which they made a big business in new medicines; in Tulp's time there were 66 apothecaries in Amsterdam. Shocked at the exorbitant prices asked for useless anti-plague medicines when Amsterdam was stricken by plague in 1635, Tulp gathered his physician and pharmacist colleagues to write the first Amsterdam pharmacopeia in 1636, the Pharmacopoea Amstelredamensis. To maintain sufficiently high standards, the Amsterdam Apothecary guild required an exam based on the pharmacopeia before new pharmacists could set up shop in Amsterdam. This pharmacopoeia became a standard work, and set an example for all the other cities in Holland. Digital facsimile of "Editio altera" also published in 1636 from the Internet Archive at this link.

Facsimile of the first Amsterdam pharmacopoeia, 1636, with an introduction by D.A. Wittop Koning. [Introd. translated into English by Miss C.F.L. Los]. Nieuwkoop: B. de Graaf, 1961.

One of the earliest accounts of beri-beri is on pp. 300-05 of this work. Tulp, notable as the demonstrator in Rembrandt’s “Anatomy Lesson”, was among the first, in the same book, to describe the ileo-caecal valve (“Tulp’s valve”). The first edition was published in 1641.

"Tulp's book has various accounts of unusual illnesses and primarily growths or carcinomas, but also has accounts of creatures brought back from Dutch East India Company ships. His drawing of a Chimpanzee is considered the first of its kind.^[2] This creature was called an Indian Satyr, since all ships cargo was considered Indonesian. However, the accompanying text claims the animal came from Angola. This drawing was copied many times and formed the basis for many theories on the origin of man. Most notably, Tulp's work and that of Jacob de Bondt (alias Jacobus Bontius) was copied and republished by Linnaeus to show a link between apes and man.^{[2]" (Wikipedia article on Observationes medicae (Tulp).}

Digital facsimile of the 1652 edition from Google Books at this link.