Novel forms of insulin delivery

Area of Science:

• Endocrinology and Metabolism
• Biomedical Engineering
• Pharmaceutical Sciences

Background:

• Subcutaneous insulin injection, despite widespread use, presents significant drawbacks including pain, inconvenience, and inconsistent pharmacokinetics.
• Current insulin delivery methods fail to replicate the direct liver delivery of endogenous insulin via the portal vein.
• The inability to 'turn off' delivered insulin poses a challenge for precise glycemic control.

Purpose of the Study:

• To review novel alternative approaches to insulin delivery beyond conventional subcutaneous injections.
• To evaluate the current status and future prospects of emerging insulin delivery technologies.
• To highlight the potential of closed-loop systems for achieving normal blood glucose homeostasis.

Main Methods:

• Review of clinically available insulin delivery devices (pen injectors, external pumps).
• Analysis of emerging technologies in development, including implantable pumps (IPPs), inhaled, nasal, and oral insulin.
• Discussion of encapsulated islets, biohybrid systems, and continuous glucose sensors (CGS).

Main Results:

• Pen injectors and external pumps are underutilized but offer convenience and basal/bolus delivery.
• Implantable pumps (IPPs) show promise but face regulatory hurdles.
• Inhaled, nasal, and oral insulin feasibility studies yield interesting findings, with pulmonary delivery being a strong candidate.
• Continuous glucose sensors (CGS) are crucial for 'closing the loop' but face technical challenges; glucose oxidase-based sensors may be available soon.

Conclusions:

• Novel insulin delivery systems offer significant potential to improve the quality of life for individuals with diabetes.
• Further research and incentives are needed to advance these technologies.
• A shift away from the notion that current insulin injection regimens are adequate is necessary.