Analytical techniques for particulate matter in intravenous solutions using membrane filters.

The introduction of particulate matter into the bloodstream has been found-both experimentally with animals and clinically with patients-to cause blockages of minor blood vessels and capillaries in key organs of the body. The most common results have been lesions and granulomas in the capillaries of the lung. The particulate matter is generally introduced into the vascular system by means of intravenous injection and infusion. Once introduced, there the contaminant will remain, the vascular system being a highly intricate, closed loop. The particulate matter will circulate in the bloodstream until it eventually finds its way into a blood vessel that is too small for it to pass. The resulting block prevents further blood circulation to the tissues in the area. In addition, there may be many types of reactions to the particulate matter by the body, such as the buildup of giant cells around it, but all result in the closure of the vessel.'-3 All administered intravenous solutions share in the dilemma, since all contain particulate matter in varying amounts, kinds, and sizes. Although the problem is recognized by the pharmaceutical industry, and vast sums are currently being diverted toward the production of particle-free I.V., it is not yet possible to produce completely particle-free solutions. The vast network of production apparatus in the pharmaceutical company precludes the achievement of a 100 percent particle-free product. Pipelines, valves, tanks, threaded connections, airborne matter and, especially, media-migrating fibrous filters all combine to contaminate the bulk product. Added particulate agents contributed by insufficiently cleaned bottles or vials and their rubber stoppers, as well as particles of glass and pieces of rubber, further complicate the problem.4--6 It is not enough to point accusingly at the I.V. solutions themselves. The solutions are administered to the patients with devices that by test have been shown to contribute at least as much and often far greater amounts of matter to the solution. Tests have been performed on administration sets, syringes and needles confirming the findings of others that these devices themselves can frequently be the major antagonists in yielding particle-free I.V. In view of the fact that the solutions and administration devices are most certainly contributing particles to the I.V., quality-control checks on them are