Study of elastomer-glass and elastomer-metal couplings for pharmaceutical primary packaging applications

With the increasing demand of insulin pens [38], the necessity to have a reliable ready-to-use product is essential to arrive first in the global competition. In particular, the goal of this thesis was to know more about the rubber liners used as sealants for the cartridges and to understand the nature of failures related to the leakage. The leakage treated in this work is related to a rubber liner malfunction for which sealing is not assured between rubber and needle during the injection of the drug. To gain information about the leakage a method was proposed. In particular, it consists in weighing the drops that leak out the rubber. Hence it is a quantification method, useful for comparing different categories. The method was first stabilized to visualize the error involved and to have a confident zero range of values when samples do not leak. Then two types of rubbers were tested, 100 samples each, to see the validity of the test and obtain useful data. The categories analyzed are those which it is thought have a major impact on the rubber sealing properties. In parallel a study in general on the rubber was done, focusing on the polyisoprene and buytl -based blends. An important study was done on the degradation phenomena in general and caused by heat in oxidative atmosphere. It was also studied the effect of the filler on the rubber properties with particular attention to the effects under high temperatures.