This article is part of a special feature on injectables that was published in the February issue of PTE Digital, available at http://www.pharmtech.com/ptedigital0211.
Advantages of prefilled syringes include:
Prefilled syringes also offer savings from a capital investment perspective. Vial washing, depyrogenation and vial component preparation equipment are not required because the syringes come presterilised and ready for use. Also, increased efficiency can be achieved by leveraging modern automated filling technology with barrier isolation systems, which can offer fill–finish lines with smaller footprints, higher throughputs and longer validation windows.
Biotech products, in particular, provide a number of unique manufacturing challenges compared with big therapeutic classes, such as anticoagulants and vaccines. The trend towards readytouse delivery systems combined with the decreasing manufacturing volume associated with biotech products and more targeted therapies poses an efficiency challenge. Batch sizes are typically smaller, requiring potential innovation and manufacturing optimisation to provide sustainable value.
For contract manufacturers, there are also complexities related to global regulatory compliance because there are marked differences in the expectations and best practices of key regulatory agencies. For example, specific structural changes needed for one client to ensure regulatory compliance may impact others using the same manufacturing line. Finding appropriate solutions to accommodate the broad spectrum of client and regulatory requirements is an intricate responsibility of utmost importance.
As with other sterile filling, such as vials, another challenge that can arise is the need to calibrate automated inspection equipment to meet the standards of multiple regional regulatory agencies, as well as client expectations. There is also often a lack of validated data to adequately handle product physicochemical limitations, such as air and/or light sensitivity, time out from refrigeration, shearing concerns and others.
There have been a number of recent innovations in prefilled syringes:
Despite the advances made so far, there is still room for further improvement. There has been an increase in the requirements for documented processing and control of the glass syringe throughout manufacture including: tube processing, forming machines (including closedloop controls), ammonium sulphate treatment, coating and annealing controls, leachable and extractable analysis, dimensional and cosmetic inspection, needle assembly control, WFI washing, siliconisation, shield assembly and nesting. The systems that support the timely availability of this data will need to evolve and improve to support the requirements of pharma and biotech companies.
As drugs evolve to more targeted applications, manufacturing flexibility will be crucial. From a CMO's perspective, innovative equipment that supports this flexibility and optimisation (e.g., equipment that can handle multiple safety shield vendors with minimal change parts) will be very important. Another improvement that would be welcomed is easy interchangeability in fill and inspection equipment for glass and plastic syringes, which would increase efficiency and provide more flexibility.
Specifically for biologics, a siliconisation process or suitable substitute is needed that has zero to minimal impact on the biological material. New tools for funnel forming combined with lower forming temperatures currently provide the lowest Tungsten content, but alternates are needed, as this would improve stability by eliminating the potentially detrimental Tungsten–protein interaction. Further understanding of product/container interactions is also required to ensure hydrolytic resistance of the syringe to prevent delamination, an issue in recent product recalls seen in the market.