The skin is a barrier between our inner body and the outside environment. Due to its specific pharmacokinetic and immunogenic properties, the dermal layer of the skin is of particular interest, both to re-consider existing drug delivery techniques and target radically new drugs and therapies.
It is challenging to develop new intradermal drug delivery systems (IDDSs) because there are many factors that can have an influence on the quality of the end result in terms of e.g. accuracy, reliability and usability. However, the interest in IDDSs has induced a realm of research and development in several domains. All these developments are, at first sight, only partially related.
We have mapped all factors that drive the development of IDDSs, comprising:
• Applications of IDDSs
• Physical and physiological properties of the dermis
• Drug formulation
• Usability of IDDSs
• Design specifications
All these factors influence the geometrical and physical specifications of IDDSs. A tentative example: in needle syringe systems, the length of the needle penetrating the skin is typically set to 1.5 mm. Any deeper length will deliver drug in the sub-cutis. Thereby sharpness and needle diameter is related to minimizing pain for the subject. But smaller needles will require bigger forces, inducing discomfort for subject and operator. On the other hand, bigger needles might be required for therapeutic cell applications. These cell types are typically sensitive to high shear rates, so automated pumps replacing operators should be consider an option for IDDSs in cell-therapeutic applications.
We present a method to link these multidisciplinary research and development lines. The links we present are visualized in a poster/presentation and could be implemented in a data structure that matches all research outcomes.
Companies that research or develop IDDSs, or parts of it, should be aware of the many factors and domains connected to their development. This is the first time that the variety of aforementioned domains from several disciplines has been brought explicitly in close mutual connection. By doing this, stakeholders can clearly see the focus of current research and; moreover, also identify gaps, to set out research roadmaps. Our linking will allow companies and research institutes to align different research lines towards the aim of developing new IDDSs that are safe, reliable, effective, and user-friendly for both subject and operator.