The company has planned to shut down the facility as part of a business transformation.
The jobs are expected to be axed around the end of 2014 or in 2015.
The Melbourne plant is now expected to focus on manufacturing specialized products such as packaging for respiratory treatments and sterile containers for medicines.
GSK corporate affairs associate director Lisa Maguire was quoted by the Sydney Morning Herald as the tablet packaging business would be transferred to factories in Aranda de Duero, Spain and Poznan, Poland.