The Glass Versus Plastic Conundrum

As in everyday life, the choice of materials we use in our processes plays a critical role in sustainability and our impact on the environment. A recent development that challenges the status quo is the introduction of plastic bottles for prepared media storage as an alternative to traditional glass. Glass is familiar. We know what it does, how it reacts, and how to use it. But plastic has a greater environmental benefit.

Glass is widely perceived as being an environmentally friendly material because it can be easily recycled. But what’s less well known is that plastic – a material that is widely frowned upon – can in fact be a more environmentally friendly alternative and less carbon expensive when considering the entire lifecycle, from production and distribution to recycling and/or end-of-life disposal. Recent studies have highlighted that glass bottles generally have a greater environmental impact than plastic bottles. (1, 2)

Glass must be subjected to temperatures of 800-900 °C to melt it down for recycling. As so much energy is needed to generate such high temperatures, this, to some extent, offsets the environmental benefits of recycling glass. By contrast, recycling plastic is far more energy efficient, requiring temperatures of just 200-250 °C.

But the switch from glass to plastic is not a simple one for drug container manufacturers. For example, in the same way a plastic bottle in a dishwasher will collapse because of temperature changes, plastic bottles can implode during the autoclaving process for terminal sterilization, which means that a redesign is needed. This has a knock-on effect in that new bottle shapes and sizes can also have a significant impact from a commercial standpoint; a larger format or a different shape may increase the amount of space taken up in an autoclave, thus reducing its capacity. This, in turn, affects the economic viability of working with such presentations.

However, plastic media bottles are nonetheless worthwhile because of the additional benefits offered by plastic. Did you know that plastic bottles can be up to 40 times lighter than their glass counterparts? In addition to being incredibly robust and shatterproof, plastic can also be fashioned into shapes beyond the traditional round glass bottle, without a significant cost penalty. The reason for this might not be obvious, but bottles with a square form factor optimize storage space. In addition to maximizing storage capacity, inventory management is streamlined and access is quicker and easier.

The lighter weight of plastic bottles also offers substantial environmental benefits in terms of transportation. The greater weight of glass bottles contributes significantly to shipping costs of media products; using square, lighter weight plastic bottles means more product can be transported in a single shipment, reducing fuel consumption, costs, and carbon emissions. This is a critical consideration in an industry that sees large volumes of products transported regularly. By switching to plastic, companies can achieve significant financial savings and efficiency gains, while contributing to their sustainability goals.

The durability of plastic bottles represents another major advantage. Glass is prone to breakage from accidental mishandling or issues during transit, leading to waste and risk of contamination and injury. Plastic is easier for operators to handle and maintain a firm grip with less effort.

Beyond environmental and safety benefits, the development of new plastic bottles also offers opportunities to increase efficiencies, enabling features to be built-in for process optimization. For example, a GL-45-compatible opening on a plastic media bottle makes sterility testing easier to perform compared with traditional glass bottles with a narrower opening. This industry standard compatibility ensures that newly introduced plastic bottles can integrate seamlessly into existing workflows, while simultaneously enhancing efficiency and reducing the risk of contamination during microbiological testing.

Getting serious about sustainability
 

The carbon expense of glass is a key reason for adopting the use of plastic in aseptic manufacturing environments. In some regions, such as Scandinavia, this is considered by pharmaceutical manufacturers to be a major factor supporting the drive towards the United Nations Sustainable Development Goals.

The development processes involved in producing a new form of packaging, however, are not without challenges, which can be costly to overcome. The need to invest in new autoclave capacity to accommodate the unique requirements of a new bottle will make the prospect unappealing to many, despite their wider benefits. But such challenges are the responsibility of companies active in this field. If we are to contribute to safeguarding the future of our planet, it's important that companies are genuinely committed to reducing their environmental impact. Nobody said this would be an easy bandwagon to jump on, or that it would lead to a huge boost in profits, but stakeholders who are serious about sustainability will want to make a positive contribution. The real challenge from a business perspective is doing so cost-effectively.

It is the responsibility of players in the sterile pharmaceutical manufacturing field to focus on creating durable, reusable solutions that offer significant advantages over traditional materials, while retaining essential levels of cleanliness and quality. Only by embracing such change, challenging the status quo, and accepting that there will be some financial cost to doing so, will we pave the way to a brighter, more sustainable future and environment to live in. Only by adopting an adaptable approach and working in partnership will it be possible to redefine the standards and impact of our processes. For anyone who might remain uncertain of the necessity of all this, it is my firm belief that validation and testing for sterility must go hand in hand with environment and sustainability.