Infusion at constant rate in vivo.

Area of Science:

• Biomedical engineering
• Pharmacokinetics
• Isotope tracing

Background:

• Achieving sustained drug delivery in vivo is crucial for therapeutic efficacy.
• Traditional infusion methods face challenges in maintaining constant levels over extended durations.
• Controlled release systems are needed for long-term biomedical applications.

Purpose of the Study:

• To evaluate the efficacy of implanted diffusion chambers for sustained in vivo infusion.
• To determine the duration and stability of constant infusion rates using this method.
• To compare the pharmacokinetic profile of infused isotopes versus injected isotopes.

Main Methods:

• Utilized an implanted diffusion chamber for subcutaneous (s.c.) infusion in vivo.
• Infused iron-59 (59Fe) isotope at a constant rate using the diffusion chamber.
• Monitored plasma 59Fe levels over an extended period.
• Determined the clearance rate and half-clearance time of injected 59Fe for comparison.

Main Results:

• Successfully maintained a constant plasma 59Fe level for 10 days via the implanted diffusion chamber.
• The s.c. implant provided a stable infusion rate over the experimental duration.
• In contrast, injected 59Fe exhibited exponential clearance with a half-clearance time of approximately 8 hours.

Conclusions:

• Implanted diffusion chambers offer a viable method for achieving prolonged, constant in vivo infusion.
• This technology significantly improves pharmacokinetic control compared to simple injection.
• The findings support the potential of diffusion chambers for long-term therapeutic delivery systems.