[Use of a dynamometer in hospital pharmacy. Its use to study the mechanical properties of plastic materials]

The stretching test is in current use in Pharmaceutical Industry to characterize the mechanical properties of materials or to control medical devices such as catheters. Given the lack of official standards in the French Pharmacopée, we present here the results of an experiment carried out in Hospital Pharmacy. The value of the results will be depending on the manual gesture of the operator and on the experimental conditions for a given material. The factors which appear to be essential are the following: numerous samples, necessary to assess a good repeatability, the stretching speed and the place of the rupture that have to be defined, so as the manual fixation of the samples. This test is interesting in Hospital Pharmacy but the methodology remains a problem so that it cannot be recommended for an occasional use, in spite of an apparent simplicity.