Two Key Questions In Platform Injection Device Development

By Iain Simpson, Associate Director, Global Medtech Practice, Cambridge Consultants

In my last column, I explained that many pharma companies have adopted an approach to advanced injection devices based on using a glass primary syringe within a platform delivery system. This approach is based on two main premises. The first is that the stability of the drug in contact with glass will have been well characterized, as the product may well already have been launched in a prefilled syringe format. The second is that the choice of a third-party platform delivery system should reduce development time and cost, as well the commercial and technical risks associated with the pharma company developing its own device.

While this has probably been a sound approach in many cases, what are the situations where alternative strategies could offer more advantage? How will future developments in the pharmaceutical sector impact the choice of optimal device strategy? These are the topics we will consider in this column.

Glass Or Polymer?

Consider the food and drink industry for a moment. Over the past 30 years, we have seen a gradual move away from glass to plastic packaging — driven by a number of factors:

• Safety And Inconvenience Of Glass Breakage: This includes total product cost, including shipping, storage, use, and disposal.
• User Convenience: Plastic moldings allow more complex forms to be produced that allow for features such as carrying handles, dispensing mechanisms, multi-compartment containers, etc.
• The Environment: Plastics present less bulk in landfill, as they can be crushed, although environmentalists might make counter arguments in favor of glass!

While glass has lost ground to plastic, it still has some advantages. To illustrate — whereas you might offer your friends wine in a plastic goblet at a picnic (where breakage becomes a concern), you probably would not at a dinner party (where the look and feel of glass is more fitting of the occasion). Not to mention, you would probably not choose plastic containers to preserve pickles or jams.

So, what is happening in the pharma industry? Glass still seems to be the mainstay in the packaging of drugs, with plastics more common where there is short-term drug contact (for example, using a disposable syringe for an injection). The main argument in favor of glass has to do with drug stability. Whereas it might be ok for a food product to have a shelf life of a few days up to a few months, this is not the case for drugs — which could be stored up to two years from manufacture to final use by a patient. Furthermore, while it might be irritating to find potato chips tasting stale after several months of storage, the consequences of degradation of drug products are far more serious.

That said, glass presents its own stability issues for some drugs. For example, tungsten deposits arising from manufacturing processes and silicones used to lubricate the piston can cause problems. The pharma industry has developed a good understanding of these types of interactions, so there has been a tendency to stick with the devil they know. Things may well change, however. For instance, in Japan, around 65% of prefilled syringes in use are made from polymer, and developments in new polymers and processes have started to address issues around stability and product cost.

Perhaps a big driver toward the use of plastics will arise from the move towards more advanced devices, such as autoinjectors (for home administration) and patch pumps (for the administration of biologic drug doses greater than what is possible in a single injection). Although the approach of building an autoinjector design around an existing glass prefilled syringe variant of a drug product has helped lifecycle management, it comes with some inherent problems. Manufacturing tolerances on glass parts are generally much greater than for injection-molded plastic parts. This makes the design of the autoinjector more challenging, and can result in the syringe being subject to large forces, and even syringe breakage. Ultimately, it could result in the recall of some market autoinjector products, with consequential loss of revenue and reputation.

On the other hand, plastic molding allows for more precise dimensions, and also allows a wider range of aspect ratios for primary packaging than for glass syringes. This suits the development of new devices like patch pumps, and more complex molded features that can simplify other parts of the design of an autoinjector. Finally, polymer devices might be able to avoid the use of silicone lubricants, hence eliminating a process step in manufacture — as well as stability and immunogenicity issues for some drugs. Within the industry, we are seeing a gradual shift of position for many pharma companies — from outright dismissal of the idea of using polymer primary packaging, to at least feeling the need to conduct some pilot stability studies to support a possible move in this direction, should the market shift that way.

Platform Or Bespoke Devices?

While the use of third-party platform devices will rightly remain the preferred approach for many pharma companies, it is not the best approach in all situations. In insulin delivery, the leading players Novo Nordisk, Sanofi, and Eli Lilly have all developed their own devices for many of their lead products. Indeed, an early decision by Novo to adopt this strategy may have been significant in their growth in market share in this area. Owning its own device technology allows a pharma company to make incremental improvements to devices to improve usability, or to address specific segments of a market by offering more personalized products. Whereas this might be possible for a third-party device, the pharma company will have less control of the process, as they will be dependent on the priorities and resources of the device provider.

Another point in the traditional model is that it is the device company, rather than the pharma company, who owns the platform, and therefore they may have limited control over where else the platform device is used. Assuming the pharma company has negotiated exclusivity for the device for a particular indication or drug type, they may still have some protection from direct competition. But, if they then seek to leverage the experience they have working with the device for another drug, they may then find they are unable to gain the rights in other areas.

So, how many platform devices are, in reality, that flexible and the design approach robust enough to serve a wide range of needs? Sometimes the device has been developed for one particular set of requirements, with the promise it can accommodate a wider range of delivery volumes, drug viscosities, and needle types. If the engineering analysis has not been done during the initial development to confirm the robustness of the design, retrospectively trying to address them in a subsequent development might be doomed to failure — and not give the perceived advantages of reuse of a platform design. Finally, a design capable of meeting a wide range of design parameters probably will not meet any set of requirements for a particular drug product as well as a bespoke design can. However, the resulting product might be less attractive, which could be an issue in increasing competitive markets.

The pharma industry might do well to be inspired by the auto industry, which, through the use of good system architecture, advanced design, and engineering tools, has moved more towards a platform approach, which has successfully addressed customer demand by offering a wide range of product variants. Pharma companies need to realize that greater use of plastic primary drug packaging might be a key element to achieving this, and to weigh the pros and cons of platform versus bespoke device and a “make or buy” approach. Given the increasing importance of devices in drug product differentiation — both for innovator drugs and reuse/improvement of existing drugs — the consequences of making a bad choice may just become that much higher.

About The Author:

Iain joined Cambridge Consultants, Global Medtech Practice in September 2011. He has a 20-year track record of multi-disciplinary technology and product development including business development, project management and technology assessment in US and European markets, the last 12 years of which has been gained in the life sciences sector in a consultancy environment, with a strong emphasis on drug delivery devices and bioinstrumentation.