The European Medicines Agency (EMA) has recently added an interesting question to its Questions & Answers section. How acceptable is filtration of particles prior to the administration of a medicinal product for parenteral use? This question addresses the problem of particles for example due to delamination of glass or rubber particles following puncture of the rubber stopper. The question is asked whether this might be compensated by a user instruction to apply a specific filter before use.
As might be expected, the answer of the EMA is an unequivocal "no". The responsibility for high-quality products can't be transferred to the patient. In certain cases, one would rather speak of a modification of the original formulation to avoid - for example - delamination of glass.
More detailed information is available in the original text of the Q&A section on the EMA website.