Pharmaceutical company PLIVA: from Nobel laureate Vladimir Prelog to global blockbuster - antibiotic azithromycin.

The history of the Croatian pharmaceutical company PLIVA from the very beginning to the status of a recognisable European and global player is described. Special attention is paid to PLIVA's cooperation with the Croatian Nobel laureate Vladimir Prelog and the invention of the proprietary antibiotic azithromycin. The antibiotic was commercialised in cooperation with the US-based company Pfizer. PLIVA's predecessor was Kaštel, Factory for Chemico-Pharmaceutical Products Joint-Stock Company. It was founded in 1920 in Karlovac, Croatia to continue operation in Zagreb in 1928. Eventually it was incorporated into the State Institute for the Production of Medicines and Vaccines bearing the acronym PLIVA (1942). In 1952, thanks to the collaboration with the organic chemist and 1975 Nobel Prize laureate Vladimir Prelog, the PLIVA Research Institute was founded. Thirty years later the research conducted by a team of scientists led to the invention of azithromycin, a new antibiotic, first member of azalides, a new class of macrolides. The core team working on azithromycin synthesis, development and patent protection (priority patent applications submitted in 1979 and 1981) included Dr Slobodan Đokić, Gabrijela Kobrehel, MSc, Dr Gorjana Lazarevski, and Dr Zrinka Tamburašev. Azithromycin was marketed globally under the trademarks of Sumamed® (PLIVA, 1988) and Zithromax® (Pfizer, 1991). It has become and still is one of the most successful and best-selling antibiotics in the world. The story of PLIVA and azithromycin shows that blockbusters can be invented based on dedication, knowledge and long-time experience despite possibly unfavourable conditions.