In 1853, shortly after qualifying as pharmacist at the University of Göttingen, Johann August (John) Kruse, moved to London in search of work. He was appointed manager of a pharmacy which was run by the medical practitioner Dr S. Weil. The following year Weil sent Kruse to Victoria, Australia to manage a new pharmacy and tobacconist's shop which he was having built at 136 Bridge Rd in Richmond. Business was slow, so in 1856 Kruse decided to open a second pharmacy 'John Kruse and Company Chemists and Druggists' in the heart of Melbourne - 207 Bourke Street. The following year the Richmond shop was destroyed by fire, so all pharmaceutical production was moved to the Bourke St premises and later to his new location at 184 Bourke St.

During the 1860s Kruse began manufacturing mineral waters, dynamite, insecticides, tonics such as his fluid magnesia and many other products. He won many awards for his health products and became a highly respected member of the pharmaceutical industry. The dynamite venture was only short lived, but Kruse continued to produce artificial waters and bottle natural mineral waters for the rest of his life. Kruse's main chemical laboratories were at 119 Flinders Street East and in 1867 were moved to 186 Flinders Lane. His main pharmacy was moved to 96 Russell St at some stage.

Due to financial difficulties Kruse was forced to sell his business in 1868 to Felton Grimwade and Company and work for them as manager of their chemical works. By the early 1870s he had regained financial independence so left the company to establish his own businesses again. He opened up a pharmacy at 31 Swanston St and in 1874 (circa) leased Victoria's premier natural springs, Clifton Springs, on the northern side of the Bellarine Peninsula, where he established a bottling plant.

During this period, there was virtually no pharmacy training or regulation in Victoria, but John Kruse was a driving force in changing this situation. He established Victoria's first training school for pharmacists (1878), was one of the founding council members of the Pharmaceutical Society of Victoria and was elected to the Pharmacy Board of Victoria for its second term (1880). Kruse's Melbourne College of Pharmacy was initially located at 100 Elizabeth Street at the Victorian Chemists' Assistants' Association, but later moved it to his home in Hanover St, Fitzroy. By 1981 Kruse was appointed foundation Director of the new College. Kruse left the College at the end of his appointment in 1885 and offer his own training courses at the 'Fitzroy School of Chemistry and Pharmacy' which he ran from his home. He also set up his own analytical chemistry practice and worked as public analyst.