Attendant to the pharmaceutical industry’s intensification in biopharmaceutical product development is the need for more effective delivery systems for large molecules. Oral administration, the widely used and common method for small-molecule drug delivery, is not a viable option for biologic-based drugs, so how can parenteral drug delivery be improved to make it easier to administer and potentially more patient- friendly? One approach, intradermal microinjection, recently took a step forward with FDA approval of an influenza vaccine delivered via this method.
Last week, Sanofi Pasteur, the vaccines division of Sanofi, reported that FDA approved the company’s supplemental biologics license application for Fluzone Intradermal, an influenza vaccine that is delivered through a microinjection system. Sanofi said the new formulation, Fluzone Intradermal, is the first influenza vaccine licensed in the US that uses a microinjection system using intradermal delivery. The vaccine is delivered with an ultra-fine needle that is 90% shorter than the typical needle used in intramuscular injection of an influenza vaccine, according to a Sanofi press release. Sanofi Pasteur also licenses microinjection intraderaml influenza vaccines, marketed as Intanza or Idflu, in 40 countries, including Australia, Canada, and countries in Europe, where it received approval in 2009.
The Fluzone Intradermal vaccine uses a prefilled microinjection system that is designed to deposit vaccine antigens into the dermal layer of the skin. The dermal layer of the skin contain a high concentration of dendritic cells, which play a role in generating an immune response. The ultra-needles used in the delivery are 0.06 inches in length, compared with typical needle lengths of 1 inch to 1.5 inches for needles used in intramuscular delivery.
Less invasive delivery methods, such as microneedle drug delivery, may present alternatives to make biopharmaceuticals an attractive option. Even though a biologic drug may offer an improved mechanism of action and clinical efficacy, that therapeutic advantage has to be balanced with how the drug is administered and delivered to gain patient acceptance and compliance. Such considerations may not factor strongly into therapies for more difficult-to-treat diseases (i.e., cancer and neurological disease), where the delivery method is secondary to finding a drug of clinical benefit. More patient-friendly approaches in drug delivery, however, are important for biopharmaceuticals to effectively compete against orally administered small-molecule drugs when these drugs may be considered to be adequate in more common therapeutic areas or in differentiating among other parenterally delivered biologic-based drugs. As the pharmaceutical industry builds its biologic-based drug pipeline and with it, a product life-cycle management strategy, “delivering the goods,” takes on a new level of importance.
For additional information on transdermal drug delivery, see the PharmTech article, “Transdermal Delivery of Vaccines and Proteins.”