Working in close cooperation with Prof. Paul Gerson Unna, a leading dermatologist of the time, he developed a process to manufacture medical plasters, and registered his first patent for it.
The date of the patent specification – March 28, 1882 – is considered to be the foundation date of the company. Beiersdorf sold the pharmacy a year later, and moved the laboratory to Altona, which is now part of the city of Hamburg.