Are these particles visible to the human eye. If you are drawing rubber woulnd't it plug up the needle or we would see it suspended in the liquid.I stand corrected. Just found an article on Science Direct with a study that showed the smaller the diameter the higher the rate of coring. 18G with 10% occurrence, 23G with 33% and higher gauges up to 70%.
"Avoiding unconscious injection of vial-derived rubber particles during intra-articular drug administration" Google it.