This article is part of PharmTech's supplement "Injectable Drug Delivery."
The rise in novel biopharmaceuticals has injected new life into the injectable delivery market. The demand for injectable
technologies is growing, says George Perros, managing director for Greystone Associates, a technology consultancy based in
New Hampshire, which in September 2009 published an analysis on Drug Delivery for Self-Adminstration: Devices, Drugs, Product Strategies and Forecasts. The following interview with Perros describes this evolving market and recent innovations.
What is your overall assessment of the future for injectables?
The advent of protein and peptide drugs has spurred the development of new delivery devices. Newer more fragile drug substances
present a delivery challenge. Nevertheless, we see not so much a revolution in injectable devices, as an evolution, as these
devices become increasingly more sophisticated, cost-effective, and safe.
Table I: Global historical volume and forecast for prefilled syringes (Greystone Associates).
What are the main drivers of this evolution?
Typically, when these biological drugs are first released onto the market, they are administered by infusion by professional
healthcare providers in a healthcare facility or an outpatient setting. This is an expensive way to administer drugs, but
it allows these drugs to be used in a controlled setting until enough data are available to establish a safety profile for
the drug that can be used to determine whether it should be approved in a form for self-administration.
Table II: Current and forecast global market share for pen injector segments (Greystone Associates).
The challenge that keeps driving device evolution focuses on how to get these drugs into the hands of the patients for self-administration
in a way that is safe, reliable, and economical. For drug products designed for self-injection, this means injection devices
that are prefilled (also referred to as combination products).
Another issue for biological drug developers is the fragile nature of the drugs themselves, which necessitates they be transported
and stored at low temperature—the so-called 'cold chain'—which adds to the cost of distribution. To avoid the problem of temperature-dependent
stability, proteins and peptides are often processed and packaged in dry or powder form. These lyophilized drugs must be reconstituted
prior to injection. Special injection devices have been developed that contain two chambers, one with the lyophilized active
ingredient, and the second for the formulation liquid or diluent. Upon activation, the powder and liquid are allowed to mix
in the correct proportions, before being injected.
The ability of patients to self-medicate reduces the economic and resource pressure of having a healthcare professional administer
the drug to the patient. So the technology challenge is to design a delivery device that ensures that the drug is preserved
properly, reconstituted properly if necessary, and administered at the right dose by a person who may have little or no experience
with injectable devices.