Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4820507 | Oral and dental hygiene preparations | Walter Ploeger, Horst Rutzen, Rudolf Lehmann | 1989-04-11 |
| 4795832 | Salicylic acid amides, their use, and a process for their production | Hans-Theo Leinen, Rudolf Lehmann | 1989-01-03 |