Point of view

For many years glass has been treated as the ‘gold standard’ in packaging of most of liquid medications and syringes. Its qualities are undeniable: it rarely reacts with the substances it holds and it doesn’t allow for fluids, vapours and oxygen to pass through. It is also transparent, which allows a quick inspection of the contents, and is easy to mould into different shapes, dependent on the purpose of the particular item.

Nevertheless, many of us are also familiar with plastic syringes, which have been around for some time. They have mostly been produced from polyethylene or polypropylene, which means they can be made a lot cheaper than their glass equivalents. However, they are not designed to hold liquid medication for longer and can only be filled right before the injection takes place. This is in contrast to glass, which can be used to store liquids for several years.

Alternative to glass

Glass, with its many advantages, is however prone to breakage, which is one of the reasons why finding a suitable alternative has been vital for both the pharmaceutical and the medical industries. Syringe producers started using a plastic called cyclic olefin copolymer (COC)/cyclic olefin copolymer (COP) several years ago and it turned out to be a much more viable solution than using cheaper polyethylene and polypropylene. COC/COP is transparent, which means that the contents can be instantly inspected for clouding or other changes. It doesn’t break as easily as glass, making it a lot more durable; this stops unnecessary wastage of expensive medications. The most important property, however, is the fact that COC/COP acts as a relatively good barrier against water vapour and oxygen and provides adequate protection for the pharmaceutical it holds.

Many drugs available on the market are expensive to produce and any wastage incurs high costs for the company; this means not only breakages, but also exposing the medication to the influence of external conditions. COC/COP syringes, thanks to their high quality, are often used as packaging for injectable biotechnologically derived drugs, which are both expensive and highly susceptible to external conditions. Hyaluronic acid, used in orthopaedics, cosmetic surgery and other treatments, as well as opthalmics, is an example of product that requires high-quality packaging, and is filled into COC/COP syringes.

No interim cleaning

The production of COC/COP syringes requires cleanroom conditions, and is usually done without human involvement, in a fully automated process. That means that syringes produced in this way don’t require interim cleaning stages, as it is in the case of glass syringe production, which involves washing the products with pharmaceutical water and eliminating glass dust. COC/COP syringes are produced using high-precision injection moulding, with cyclic olefin polymer granules being poured into the injection moulding machine. This allows for tight tolerances and accurate geometries of the ready product, which means that less medication residue remains in the syringe after the injection — it is an important argument in the case of expensive pharmaceuticals, where any quantity of wasted product incurs large costs.

Of course syringes are used for a variety of drugs and there isn’t one type or material that will suit all applications perfectly. Cost is very often the deciding factor in decision-making processes of healthcare providers, provided it doesn’t have implications on the safety of the patients. Increasingly the option of ready-to-fill syringes wins, as it becomes more common for patients to dispense their medications themselves or have administered at home by a health professional or another qualified person. This saves both the personnel time and costs, both of which are limited in modern healthcare systems.

Taking all this into consideration, cooperation of syringe manufacturers and pharmaceutical companies is extremely important. Collaboration at the very early stages of drug development can save a lot of time and money spent on researching the best syringe solution for a particular medication.

Importance of choice

It is vital that options exist for the pharmaceutical industry, especially where syringes are concerned. While COC/COP might be the best solution for innovative biotechnologically developed drugs, it is still more expensive than glass and does not possess exactly the same properties — glass is more gas/vapour permeable and inert and it will continue to be a viable option for many pharmaceutical manufacturers. In time, however, COC/COP syringes will certainly continue to develop and will be used increasingly for expensive applications requiring less wastage. In the case of some medications there are also legal requirements that need to be followed. The environment in which medication is administered is also an important factor in choosing the right syringe for the job: cheaper syringes made of polyethylene or polypropylene can be used in hospitals, medical centres or clinics, but for self-medication ready-to-fill syringes might be the best option.

This article used materials provided by Gerresheimer (www.gerresheimer.com) and Schott (www.schott.com).