Microbiological inspections of different medical devices

The microbiological quality control represents a cornerstone in the production process of pharmaceutical products and Medical Devices (MDs). In both the pharmaceutical and MD industries, along with evolving regulatory requirements, products of greater complexity are elevating the challenges related to maintaining microbiological integrity. For a given inactivation treatment, the probability of bacterial survival is determined by number and resistance of microorganisms and by the environment in which the organisms live. Nevertheless, the sterility of an individual item in a population of sanitized products cannot be ensured in the absolute sense. For the first time, different MDs were analyzed from the microbiological viewpoint. Following health warnings, several kinds of MDs were examined for investigating their real compliance with the sterility requirements expected for the specific product category. According to the European Pharmacopeia, mesophilic viable microorganisms, faecal bacteria, moulds and yeasts, P. aeruginosa, S. aureus and other microbial parameters of interest depending on the circumstances were determined. Culture methods and biochemical confirmation tests were performed. The sterility expected for some MDs under test, such as saline solution for contact lens and dentistry graft devices, was not always confirmed and pathogens were isolated and identified. The microbiological evaluation of other MDs for which the sterility was not required (auricular cones, vaginal douching and denture adhesive powder) was performed assimilating them to pharmaceutical product for topic use. In some cases, high numbers were observed and environmental potential pathogens were identified. These results emphasize the fundamental role of good manufacturing practices in this production area and stress the need for closely monitoring any step of the production chain.