Despite consumer demand for needle-free methods of drug delivery, traditional injection remains the dominant paradigm. Prefilled injection devices, which are quicker and easier to use and enable premeasured and presterilized dosing, are being increasingly integrated into the plans of pharmaceutical and biotechnology companies. According to a report from Greystone Associates in Amherst, New Hampshire, prefilled syringes are replacing vials both in terms of injections and sector revenue, and as this trend continues during the next four years, the number of tailored, injectable drug products reaching the market is set to escalate.

But this doesn't mean that integrating the technology will be easy. Stability is a major issue. "Unlike glass vials, the drug needs to be stable for protracted periods of time while in contact with the different synthetic materials that comprise the syringe. Therefore, stability testing is a big necessity," said Greystone Market Analyst David Clark in an interview with Pharmaceutical Technology Europe.

Drug stability, however, is improving as advances such as new materials and manufacturing processes are made to the design of prefilled syringes. Advances are also being made in the field of needle-free injections, which Clark says will "play a part" in the sector, adding that, "the major movement will be within the injectable-device sector; from syringes to pen injectors and auto injectors."

The use of prefilled injection devices varies depending on the drug class. "For example, recombinant protein drugs are very expensive to manufacture and are, therefore, almost always available in prefilled syringes," said Clark. "This is more economical than having to overfill vials to account for caregiver variations or eliminating air bubbles in the syringe prior to injection, etc." He also adds that vaccines, which are relatively less expensive, are also supplied in prefilled syringes because it saves time when vaccinating large numbers of patients. "This is a major advantage in undeveloped areas such as sub-Saharan Africa where vaccination is essential to improving quality of life and reducing the incidence of disease."

Looking forward, Clark expects the sector to grow even more during the next few years. "A greater percentage of drugs in a given drug class will become available in prefilled syringes," he said. "In particular, this relates to drugs indicated for chronic conditions; self-administration will also become available in automated injection devices."

Stephanie Sutton is an assistant editor at Pharmaceutical Technology Europe.